The Potential of 233U/236U as a Water Mass Tracer in the Arctic Ocean ...

• Main Authors: Chamizo, Elena, Christl, Marcus, López-Lora, Mercedes, Casacuberta, Núria, Wefing, Anne-Marie, Kenna, Timothy C.
• Format: Article in Journal/Newspaper
• Language: English
• Published: ETH Zurich 2022
• Subjects: Arctic; Arctic Ocean
• Online Access: https://dx.doi.org/10.3929/ethz-b-000541798; http://hdl.handle.net/20.500.11850/541798

This study explores for the first time the possibilities that the 233U/236U atom ratio offers to distinguish waters of Atlantic or Pacific origin in the Arctic Ocean. Atlantic waters entering the Arctic Ocean often carry an isotopic signature dominantly originating from European reprocessing facilities with some smaller contribution from global fallout nuclides, whereas northern Pacific waters are labeled with nuclides released during the atmospheric nuclear testing period only. In the Arctic Ocean, 233U originates from global fallout while 236U carries both, a global fallout and a prominent nuclear reprocessing signal. Thus, the 233U/236U ratio provides a tool to identify water masses with distinct U sources. In this work, 233U and 236U were analyzed in samples from the GN01 GEOTRACES expedition to the western Arctic Ocean in 2015. The study of depth profiles and surface seawater samples shows that: (a) Pacific and Atlantic waters show enhanced signals of both radionuclides, which can be unraveled based on ... : Journal of Geophysical Research: Oceans, 127 (3) ...