Aerosols characterization in a forested site in Québec, Canada

Three AERAS low pressure 11 stage cascade impactors with rotatable collecting plates (LPCR) were installed at the Duchesnay forest station near Québec City and four low pressure inertial collectors (LPIC) were installed in the forest. The analysis of the aerosol deposits was performed by static fast atom beam mass spectroscopy (FABMS); SIMS and ESCA analyses were also made. The morphological characterization and the elemental volumetric composition of the aerosols were established by a scanning electron microscope equipped with an X-ray dispersive energy analyser. Micro-weighting of the aluminium substrate before and after the sampling by the AERAS impactor enabled the study of the mass-size-distribution of the aerosols according to their aerodynamic equivalent diameter. Example of the results obtained are presented in relation to air parcels' trajectories. This study has shown that it is possible to characterize the aerosols according to the origin and trajectories of the air mass with which they travel; sources along the tracks have been shown to contribute to the aerosol loading of the air masses.