Tracing Ocean Circulation and Mixing From the Arctic to the Subpolar North Atlantic Using the 129I–236U Dual Tracer ...

• Main Authors: Dale, Duncan, Christl, Marcus, Vockenhuber, Christof, Macrander, Andreas, Ólafsdóttir, Sólveig, Middag, Rob, Casacuberta, Núria
• Format: Text
• Language: English
• Published: ETH Zurich 2024
• Subjects: tracer; artificial radionuclides; Iceland; Nordic Seas; I-129; U-236; Arctic Ocean; Greenland; Greenland-Scotland Ridge; North Atlantic
• Online Access: https://dx.doi.org/10.3929/ethz-b-000685503; http://hdl.handle.net/20.500.11850/685503

This study represents the first use of the artificial radionuclides 129I and 236U, released into the ocean mainly from Nuclear Reprocessing Plants, as a dual tracer in the vicinity of Iceland with novel estimation of ocean circulatory pathways and mixing in the region. Iceland lies at the gateway to the Arctic where warm, saline Atlantic waters interact with waters of Arctic origin in ways that have critical consequences for the strength and stability of the Atlantic Meridional Overturning Circulation. Many of these interactions are not yet fully understood, such as how Atlantic water circulates around the Arctic Ocean and Nordic Seas and the composition and fate of the major overflows of the Greenland-Scotland Ridge. Using new and previous measurements of 129I and 236U in seawater, we present a new method of appraising water mass provenance and mixing in the form of the 129I–236U dual mixing plot. With this method, we estimate that at least half the Atlantic-origin water entering the Arctic Ocean circulates ... : Journal of Geophysical Research: Oceans, 129 (7) ...