Evolution of 231Pa and 230Th in overflow waters of the North Atlantic ...

• Main Authors: Deng, Feifei, Henderson, Gideon M., Castrillejo, Maxi, Pérez, Fíz F., Steinfeldt, Reiner
• Format: Article in Journal/Newspaper
• Language: English
• Published: ETH Zurich 2018
• Subjects: Labrador Sea; North Atlantic
• Online Access: https://dx.doi.org/10.3929/ethz-b-000313192; http://hdl.handle.net/20.500.11850/313192

Many palaeoceanographic studies have sought to use the 231Pa∕230Th ratio as a proxy for deep ocean circulation rates in the North Atlantic. As of yet, however, no study has fully assessed the concentration of, or controls on, 230Th and 231Pa in waters immediately following ventilation at the start of Atlantic meridional overturning. To that end, full water-column 231Pa and 230Th concentrations were measured along the GEOVIDE section, sampling a range of young North Atlantic deep waters. 230Th and 231Pa concentrations in the water column are lower than those observed further south in the Atlantic, ranging between 0.06 and 12.01 µBq kg−1 and between 0.37 and 4.80 µBq kg−1, respectively. Both 230Th and 231Pa profiles generally increase with water depth from surface to deep water, followed by decrease near the seafloor, with this feature most pronounced in the Labrador Sea (LA Sea) and Irminger Sea (IR Sea). Assessing this dataset using extended optimum multi-parameter (eOMP) analysis and CFC-based water mass ... : Biogeosciences, 15 (23) ...