Particle size and aerosol iron solubility: A high-resolution analysis of Atlantic aerosols

Aerosol samples were collected in the North Atlantic Ocean during June–August, 2003. Aerosols were divided into nine size fractions ranging from > 18 μm to < 0.056 μm. Total element concentrations were measured by energy dispersive X-ray fluorescence to determine the size distribution of biogeochemically important elements. The solubility of Fe and other elements was measured in ultrapure deionized water to investigate the relationship between particle size and aerosol solubility. We found that the majority of soluble aerosol Fe was on particles of ≥ 1 μm aerodynamic diameter. Aerosol Fe solubility was somewhat variable but in general, aerosol Fe solubility did not increase with decreasing particle size.