| Summary: | Our understanding of glacial flour dust storm delivery of iron to the Gulf of Alaska (GoA) is limited. We interpret concurrent time-series satellite, meteorological, and aerosol geochemical data from the GoA to examine how inter-annual variability in regional weather patterns impacts offshore aerosol glacial iron transport. In 2011, when a northerly Aleutian Low (AL) was persistent during fall, dust emission was suppressed and highly intermittent due to prevalent wet conditions, low winds and a deep early season snowpack. Conversely, in 2012, frequent and prolonged fall dust storms and high offshore glacial iron transport were driven by dry conditions and strong offshore winds generated by persistent strong high pressure over the Alaskan interior and Bering Sea and a southerly AL. Remarkable inter-annual variability in offshore glacial aerosol iron transport indicates that the role of glacial dust in GoA nutrient cycles is likely highly dynamic and particularly sensitive to regional climate forcing.
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