Publication Date:
2018-10-08
Description:
This study presents the data on 129I and 236U concentrations in seawater samples and sea
ice cores obtained during two expeditions to the Arctic Ocean that took place onboard R/V Polarstern
(PS94) and R/V Lance (N-ICE2015) in summer 2015. Carbon-14 was also measured in the deep water
samples from the Nansen, Amundsen, and Makarov Basins. The main goal was to investigate the
distribution of 129I and 236U in a transect from the Norwegian Coast to the Makarov Basin to fully exploit
the potential of combining 129I and 236U as a dual tracer to track Atlantic waters throughout the Arctic
Ocean. The use of the 129I/236U and 236U/238U atom ratios allowed identifying a third Atlantic branch that
enters the Arctic Ocean (the Arctic Shelf Break Branch) following the Norwegian Coastal Current that
carries a larger proportion of the European reprocessing plants signal compared to Fram Strait Branch
Water and Barents Sea Branch Water. The combination of 129I and 236U also allowed quantifying the
different proportions of the La Hague stream, the Scottish stream, and Atlantic waters forming the three
Atlantic branches of the Arctic Ocean Boundary Current. The results show that the 129I/236U atom ratio
can now be used to identify the different Atlantic branches entering the Arctic Ocean. New input functions
for 129I, 236U, and 129I/236U have also been described for each branch, which can be further used for
calculation of transit time distributions of Atlantic waters.
Repository Name:
EPIC Alfred Wegener Institut
Type:
Article
,
isiRev
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