Strong Margin Influence on the Arctic Ocean Barium Cycle Revealed by Pan-Arctic Synthesis.

Autor: Whitmore LM; School of Ocean Science and Engineering University of Southern Mississippi Stennis Space Center MS USA.; Now at College of Fisheries and Ocean Sciences University of Alaska Fairbanks Fairbanks AK USA., Shiller AM; School of Ocean Science and Engineering University of Southern Mississippi Stennis Space Center MS USA., Horner TJ; NIRVANA Laboratories Woods Hole Oceanographic Institution Woods Hole MA USA., Xiang Y; Department of Ocean Sciences University of California Santa Cruz CA USA., Auro ME; NIRVANA Laboratories Woods Hole Oceanographic Institution Woods Hole MA USA., Bauch D; GEOMAR Helmholtz Centre for Ocean Research Kiel Germany., Dehairs F; Department of Analytical, Environmental and Geochemistry Vrije Universiteit Brussel Brussels Belgium., Lam PJ; Department of Ocean Sciences University of California Santa Cruz CA USA., Li J; Department of Earth Ocean & Atmospheric Sciences University of British Columbia Vancouver BC Canada., Maldonado MT; Department of Earth Ocean & Atmospheric Sciences University of British Columbia Vancouver BC Canada., Mears C; Institute of Carbon Cycles Helmholtz Centre Hereon Geesthacht Germany., Newton R; Lamont-Doherty Earth Observatory Columbia University New York NY USA., Pasqualini A; Department of Earth and Environmental Engineering Columbia University New York NY USA., Planquette H; University of Brest CNRS IRD Ifremer LEMAR Plouzane France., Rember R; International Arctic Research Center University of Alaska Fairbanks Fairbanks AK USA., Thomas H; Institute of Carbon Cycles Helmholtz Centre Hereon Geesthacht Germany.
Jazyk: angličtina
Zdroj: Journal of geophysical research. Oceans [J Geophys Res Oceans] 2022 Apr; Vol. 127 (4), pp. e2021JC017417. Date of Electronic Publication: 2022 Mar 30.
DOI: 10.1029/2021JC017417
Abstrakt: 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 (δ 138 Ba) 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 δ 138 Ba 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.
(© 2022 The Authors.)
Databáze: MEDLINE
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