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In the changing Arctic Ocean, organic pollutants' transport and biogeochemical processes are strongly influenced by their particulate export on the broad continental shelf. To better evaluate the vertical particulate export of polycyclic aromatic hydrocarbons (PAHs), seawater samples were collected from the Bering Sea, Chukchi Sea, and Canada Basin with the first application of 210Po/210Pb disequilibrium during the summer of 2012. Dissolved PAHs (1.1–19 ng L−1, mean 5.2 ± 3.6 ng L−1) showed spatial distinctions, with high values on the Bering Shelf and low values in the Chukchi Sea, while particulate PAHs (1.0–12 ng L−1, mean 5.0 ± 3.5 ng L−1) showed high levels in the nutrient‐rich Bering Shelf Water layer. According to the 210Po/210Pb deficit on the Bering Shelf, the export fluxes of particulate PAHs ranged from 1,201 ± 276 to 3,650 ± 1,570 ng m−2 d−1, and their residence time ranged from 55 ± 23 to 133 ± 31 days. From the Bering Shelf to the Chukchi Sea, the decreased inventories of dissolved PAHs were positively related to their vertical particulate export fluxes (R2 = 0.62), suggesting the “Shelf Sink Effect” on PAHs.

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The Arctic Ocean, linking the Atlantic Ocean and the Pacific Ocean, is a fundamental node in the global hydrological cycle and thermohaline circulation (Carmack et al., 2016;Talley et al., 2011). A major inflow to the Arctic Ocean comes from the Atlantic through the Fram Strait and the Barents Sea, with a minor inflow from the Pacific side through Bering Strait (Liu, Chen, et al., 2021;Y. Ma et al., 2018). The outflow from the Arctic Ocean, being cold and fresh, is mainly conveyed by East Greenland Current through the Fram Strait, which is the only deep channel allowing energy and materials to exchange between the Arctic Ocean and other oceans (X. Wang et al., 2021). The Arctic is the most sensitive area worldwide and is undergoing visible and less visible changes such as warming, refreshing, and sea ice loss (Dai et al., 2019;Ko et al., 2020;Morison et al., 2012). External to the Arctic Ocean, the bordering subarctic oceans are undergoing substantial changes in heat, salt, and biogeochemical properties, therefore amplifying the climate response of the Arctic Ocean (Steele & Boyd, 1998).

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