| Summary: | Atmospheric deposition of dust is an important pathway supplying nutrient trace elements to the surface water of remote oceans. Recent warming in the sensitive polar regions might potentially enhance the regional dust emission. Bulk and size-segregated aerosol samples were collected in the western Antarctic Peninsula and the Arctic Ocean to characterize atmospheric trace elements and to evaluate the importance of aeolian dust input to the high latitude marine ecosystems. The objectives of this study are to (1) characterize atmospheric trace elements in aerosols and identify their major sources, (2) quantify the atmospheric dust deposition, and (3) assess the aerosol iron bioavailability through characterizing the aerosol Fe mineralogy and oxidation states. Sampling of both size-segregated and bulk aerosol particles was carried out at Palmer Station in the western Antarctic Peninsula and during a cruise in the Arctic Ocean. Results from the western Antarctic Peninsula showed that trace elements in aerosols over this region are primarily derived from (1) regional crustal emissions, (2) long-range transport, and (3) sea salt aerosols. Elements derived from crustal sources (Al, P, Ti, V, Mn, Ce) with crustal enrichment factors (EFcrust) <10 were dominated by the coarse-mode particles (>1.8 µm) and peaked around 4.4 µm in diameter. Other elements including Ca, Ni, Cu, Zn, and Pb showed EFcrust > 10. The particle size distribution of aerosol Pb was dominated by fine particles and peaked at 0.14–0.25 µm, suggesting an anthropogenic contribution through long-range transport. The estimated dry deposition fluxes of mineral dust during the 2016-2017 austral summer in the Antarctic Peninsula ranged from 0.65 to 28 mg m−2 yr−1 with a mean of 5.5±5.0 mg m−2 yr−1, which were lower than most fluxes reported previously in coastal Antarctica. The Fe minerals in the dust particles over the Antarctic Peninsula were predominantly hematite and biotite with a minor fraction of pyrite and ilmenite. The aerosol Fe oxidation ...
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