Speciation of organic aerosols in the Saharan Air Layer and in the free troposphere westerlies

Abstract

Speciation of organic aerosol was performed in the westerlies and in the Saharan Air Layer, where biogenic secondary organic aerosol (oxidation of isoprene and alpha-pinene) and primary combustion compounds (hopanes and PAHs) were observed. In the Saharan Air Layer, species (saccharides) linked to soil emission – plant tissues and microorganisms – in the inner Sahara were also identified, whereas in the westerlies biomass burning compounds (e.g. levoglucosan) from North America also occurred.