Tracing water masses with I-129 and U-236 in the subpolar North Atlantic along the GEOTRACES GA01 section ...

Pathways and timescales of water mass transport in the subpolar North Atlantic Ocean (SPNA) have been investigated by many studies due to their importance for the meridional overturning circulation and thus for the global ocean. In this sense, observational data on geochemical tracers provide comple...

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Bibliographic Details
Main Authors: Castrillejo, Maxi, Casacuberta, Núria, Christl, Marcus, Vockenhuber, Christof, Synal, Hans-Arno, Garcia-Ibanez, Maribel I., Lherminier, Pascale, Sarthou, Géraldine, Garcia-Orellana, Jordi, Masque, Pere
Format: Article in Journal/Newspaper
Language:English
Published: ETH Zurich 2018
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Online Access:https://dx.doi.org/10.3929/ethz-b-000295501
http://hdl.handle.net/20.500.11850/295501
Description
Summary:Pathways and timescales of water mass transport in the subpolar North Atlantic Ocean (SPNA) have been investigated by many studies due to their importance for the meridional overturning circulation and thus for the global ocean. In this sense, observational data on geochemical tracers provide complementary information to improve the current understanding of the circulation in the SPNA. To this end, we present the first simultaneous distribution of artificial 129I and 236U in 14 depth profiles and in surface waters along the GEOVIDE section covering a zonal transect through the SPNA in spring 2014. Our results show that the two tracers are distributed following the water mass structure and that their presence is largely influenced by the global fallout (GF) and liquid effluents discharged to north-western European coastal waters by the Sellafield and La Hague nuclear reprocessing plants (NRPs). As a result, 129I concentrations and 236U∕238U atom ratios and 129I∕236U atom ratios display a wide range of values: ... : Biogeosciences, 15 (18) ...