Atmospheric aerosol during 2005/06 harmattan season at Kwabenya-near Accra, (Ghana): possible sources

Principal component analysis (PCA) together with regression analysis was used to develop a model to characterise possible source of aerosol particulate matter (PM) collected during the 2005/06 harmattan. Species generated by gravimetric, EDXRF and reflectometric techniques were used, namely; mass, elemental and black carbon (BC) concentrations. Over 26 elements were identified in the aerosol samples collected; only 17 were used in the model for the coarse fraction and 7 for the fine fraction. This was because some were below detection limit or some elements had a lot of missing values. The coarse fraction contained over 90% of the mass while the fine fraction contained more BC. Two clear source profiles were identified in the fine fraction of the aerosol and four source profiles in the coarse fraction. There was very good agreement. R2 values of 0.95 and 0.93 for coarse and fine respectively, between the experimental particulate mass and the modeled mass. (au)