Trends in the solubility of iron in dust-dominated aerosols in the equatorial Atlantic trade winds: importance of iron speciation and sources.

摘要: [1] We present measurements of the solubility Fe(II) and Fe(III) extracted from bulk size-fractionated African dust collected in summer trade winds at Barbados, West Indies. Iron solubilities typically ranged 1% to 3%. dominates iron over entire range particle sizes. At mineral concentrations below about 5 ug/m3 Fe(II), believed be largely derived anthropogenic biomass burning sources, becomes increasingly important. Samples containing large soluble fractions high Fe(II)/Fe(III) ratios are associated with South Atlantic back trajectories; gray coloration filters suggests that source may southern Africa. In general, much variability Fe is linked concentration changes. Vanadium often used as a tracer impacts. Although many our samples yielded V/Ti greater than average crustal abundances, we could find no relationship between enrichment V solubility. Our results quite similar those obtained by others despite fact were made diverse ocean regions protocols different all cases. This uniformity implies factors controlling aerosol inherent properties aerosols themselves not procedures extract iron. suggest transport models focus on role biogeochemistry must take into account origin order better model