Wintertime enhancements of sea salt aerosol in polar regions consistent with a sea ice source from blowing snow

摘要: Abstract. Sea salt aerosols (SSA) are generated via air bubbles bursting at the ocean surface as well by wind mobilization of saline snow and frost flowers over sea-ice-covered areas. The relative magnitude these sources remains poorly constrained polar regions, affecting our ability to predict their impact on halogen chemistry, cloud formation, climate. We implement a blowing flower emission scheme in GEOS-Chem global chemical transport model, which we validate against multiyear (2001–2008) situ observations SSA mass concentrations three sites Arctic, two coastal Antarctica, from 2008 ICEALOT cruise Arctic. A simulation including only open emissions underestimates factors 2–10 during winter–spring for all ground-based ship-based observations. When added, model is able reproduce observed wintertime concentrations, with bias decreasing range −80 −34 % −2 +9 % emissions. find that parameterization cannot fully explain high displays seasonal cycle too rapidly early spring. Furthermore, day-to-day variability better reproduced parameterization. Over Arctic (> 60° N) (Antarctic, > 60° S), calculate submicron account 1.0 Tg yr−1 (2.5 Tg yr−1), while lead 0.21 Tg yr−1 (0.25 Tg yr−1) compared 0.78 Tg yr−1 (1.0 Tg yr−1) ocean. Blowing largest regions where persistent strong winds occur sea ice (east Greenland, central Beaufort Sea, Ross Weddell seas). In contrast, cold temperatures leads co-located (over Canadian Archipelago, Siberia, off Ronne shelves). Overall, suggest likely be dominant source winter, playing much smaller role.