Scattering properties and mass concentration of local and long-range transported aerosols over the South Western Iberia Peninsula

Data on aerosol spectral scattering coefficients and mass concentration, measured in Évora (Portugal) in 2006, were analysed. The average aerosol scattering coefficient, at the wavelength of 550 nm, and PM10 mass concentration for 2006 time period were, respectively, 46 M m−1 and 24 μg m−3. Both quantities presented high variability, the former in the range of 13–133 M m−1 and the later within the range 5–99 μg m−3. Desert dust from Sahara region, biomass burning aerosols from forest fires, and anthropogenic pollution from Europe and Iberian Peninsula were observed at the site. The aerosol mass scattering efficiency was estimated for different aerosol types during episodes of high particle concentration. The mean values were found to be 0.97 m2 g−1 for desert dust, 2.48 m2 g−1 for forest fires and 4.55 m2 g−1 for anthropogenic pollution.