Sources and processes of iron aerosols in a megacity in Eastern China

Abstract. Iron (Fe) in aerosol particles is a major external source of micronutrients for marine ecosystems and poses potential threat to human health. To understand the impacts Fe, it essential quantify sources dissolved Fe total Fe. In this study, we applied receptor modeling first time apportion fine collected under five different weather conditions Hangzhou megacity Eastern China, which upwind East Asian outflow. Results showed that solubility (dissolved Fe) was largest on fog days (6.7 ± 3.0 %), followed by haze (4.8 1.9 dust (2.1 0.7 clear (1.9 1.0 rain (0.9 0.5 %) days. Positive matrix factorization (PMF) analysis suggested industrial emissions were contributor (44.5 %–72.4 (39.1 %–55.0 %, except days) during haze, fog, dust, Transmission electron microscopy individual > 75 % Fe-containing internally mixed with acidic secondary species Furthermore, significant positive correlations acidity/total liquid water content. These results indicated wet surface promotes heterogeneous reactions between aerosols, contributing high solubility.