COMPARISON OF THE SOURCE LOCATIONS AND SEASONAL PATTERNS FOR ACIDIC SPECIES IN PRECIPITATION AND AMBIENT PARTICLES IN SOUTHERN ONTARIO, CANADA

The Potential Source Contribution Function (PSCF) is a probability function based on the air parcel trajectory data coupled with information regarding the nature of the contaminants measured in that air parcel. The PSCF value is the ratio of the probability of a contaminated air parcel having traversed a 1-degrees latitude by 1-degrees longitude area to the probability that any air parcel traversed that area. Regions with high PSCF values thus have a higher probability of contributing pollutants to the measured concentrations at the receptor site. Previously, PSCF analysis has been used on precipitation chemistry data obtained from the Acidic Precipitation in Ontario Study (APIOS) to locate the sources of the acidic precipitation. In this present study, the methodology has been applied to both precipitation samples and particulate samples collected by the APIOS network. Analyses have been performed separately for the winter and summer seasons so that the comparison between particles and precipitation and/or winter and summer can be made. From these results it is possible to identify the possible source locations for the observed constituents and at the same time, derive information on atmospheric process by this study.