Evolution of organic and inorganic components of aerosol during a Saharan dust episode observed in the French Alps

[摘要] A Saharan dust event was observed in a rural area in the Maurienne Valley(French Alps) in summer 2000. Detailed data on PM₁₀, particle numbers,and aerosol chemistry (ionic species and Elemental Carbon (EC) and OrganicCarbon (OC)) are presented. The comparative evolutions of particle numbersand chemistry (calcium, sodium, and sulfate) show that the overall periodincluded two episodes of dust particles with very distinct chemistry,followed by an episode with a large increase of the concentrations ofspecies with an anthropogenic origin. The overall data set does not indicatelarge interactions between the dust particles and compounds fromanthropogenic origin (sulfate, nitrate) or with organic carbon, all of thesespecies showing very low concentrations. Simplistic calculations indicatethat these concentrations are consistent with our current knowledge ofadsorption processes of gases on mineral dust in a clean air mass.

[学科分类] 大气科学