| Summary: | Trace metals (manganese, iron, nickel, copper, zinc, and cadmium) are essential micronutrients for phytoplankton and can be used as tracers of oceanic processes. The supply of trace metals to the Western Arctic was thought to be dominated by macronutrient-rich Pacific waters entering through the Bering Strait and modified by uptake and regeneration on the Chukchi Shelf. However, the first high resolution (~6km) trace metal measurements in the strait (July 2021) show large variability in trace metal concentrations across the strait and a close relationship with salinity. The previously unsampled Alaskan Coastal Water has unexpectedly high trace metal concentrations, while the macronutrient-rich Anadyr Water has surprisingly low trace metal concentrations. We make the first estimates of trace metal flux from the Pacific to the Arctic through the Bering Strait and find they are elevated despite the comparatively small volume transport and, for some metals, exceed the Arctic to Atlantic export. Funding provided by: National Science Foundation Crossref Funder Registry ID: https://ror.org/021nxhr62 Award Number: 1758565 Funding provided by: Cooperative Institute for Climate, Ocean, and Ecosystem Studies, University of Washington Crossref Funder Registry ID: http://dx.doi.org/10.13039/100021076 Award Number: Funding provided by: National Science Foundation Crossref Funder Registry ID: https://ror.org/021nxhr62 Award Number: 2153942 Trace metal and macronutrient samples were collected July 10-16, 2021, from the R/V Norseman II during an annual Bering Strait (BS) mooring and hydrographic cruise, which sampled the eastern Bering Strait (eBS) and the A3 line (AL) sections at 6-10km resolution. Water was collected using an air-diaphragm pump (PTFE, Wilden) with inline filtration (0.2 um, Acropak), pumping water from ~5m ("surface") or ~25-45m depth ("bottom"), sufficient resolution to define the strait's typically two-layer stratification (Woodgate et al., 2015). Samples were collected into acid-cleaned 250 mL low ...
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