Distributions of total and size-fractionated particulate <sup>210</sup>Po and <sup>210</sup>Pb activities along the North Atlantic GEOTRACES GA01 transect: GEOVIDE cruise
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Published:2018-09-14
Issue:17
Volume:15
Page:5437-5453
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ISSN:1726-4189
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Container-title:Biogeosciences
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language:en
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Short-container-title:Biogeosciences
Author:
Tang YiORCID, Castrillejo MaxiORCID, Roca-Martí MontserratORCID, Masqué PereORCID, Lemaitre Nolwenn, Stewart GillianORCID
Abstract
Abstract. Vertical distributions of total and particulate polonium-210
(210Po) and lead-210 (210Pb) activities in the water
column were measured at 11 stations in the North Atlantic during the
GEOTRACES GA01 transect: GEOVIDE cruise in May–June 2014.
Total 210Po activity was on average 24 % lower than
210Pb activity in the upper 100 m, and it was closer to unity in
the mesopelagic (100–1000 m). The partitioning coefficients
(Kd) along the transect suggest the preferential association of
210Po relative to 210Pb onto particles. The prominent
role of small particles in sorption was confirmed by the observation that
over 80 % of the particulate radionuclide activity was on small
particles. To account for the observed surface water
210Po ∕ 210Pb disequilibria, particulate radionuclide
activities and export of both small (1–53 µm) and large (>53 µm) particles must be considered. A comparison between the
GEOVIDE total particulate 210Po ∕ 210Pb activity
ratios (ARs) and the ratios in previous studies revealed a distinct
geographic distribution, with lower particulate ARs in the high-latitude
North Atlantic (including this study) and Arctic in relation to all other
samples. For the samples where apparent oxygen utilization (AOU) was
calculated at the same depth and time as the
210Po ∕ 210Pb AR (40 stations including this study),
there was a two-phase correlation between the total particulate AR and AOU,
likely reflecting the nature of the particles and demonstrating the forces of
remineralization and radionuclide decay from particles as they age.
Funder
Division of Ocean Sciences
Publisher
Copernicus GmbH
Subject
Earth-Surface Processes,Ecology, Evolution, Behavior and Systematics
Reference76 articles.
1. Amacher, J., Neuer, S., and Lomas, M.: DNA-based molecular fingerprinting of
eukaryotic protists and cyanobacteria contributing to sinking particle flux
at the Bermuda Atlantic time-series study, Deep-Sea Res. Pt. II, 93, 71–83, https://doi.org/10.1016/j.dsr2.2013.01.001,
2013. 2. Bacon, M. P.: 210Pb and 210Po results from F.S.
“Meteor” cruise 32 in the North Atlantic, PANGAEA, https://doi.org/10.1594/PANGAEA.604014, 1977. 3. Bacon, M. P., Spencer, D. W., and Brewer, P. G.:
210Pb ∕ 226Ra and
210Po ∕ 210Pb disequilibria in seawater and suspended
particulate matter, Earth Planet. Sc. Lett., 32, 277–296, https://doi.org/10.1016/0012-821X(76)90068-6, 1976. 4. Bacon, M. P., Brewer, P. G., Spencer, D. W., Murray, J. W., and Goddard, J.:
Lead-210, polonium-210, manganese and iron in the Cariaco Trench, Deep-Sea
Res. Pt. A, 27, 119–135, https://doi.org/10.1016/0198-0149(80)90091-6, 1980a. 5. Bacon, M. P., Spencer, D. W., and Brewer, P. G.: Lead-210 and Polonium-210 as
Marine Geochemical Tracers: Review and Discussion of Results from the
Labrador Sea, Natural radiation environment III, edited by: Gesell, T. F. and
Lowder, W. M., 1, 473–501, 1980b.
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