Abstract
The concentrations of three different fractions of particulate matters including PM2.5, PM10, and TSP were compared between the Asian Dust (AD) and non-AD (NAD) periods during the spring season of 2001. For the purpose of this comparative analysis, the data sets were obtained from four different observatory sites located within the city boundary of Seoul that concurrently measure those three fractions of PM at hourly intervals. According to our study, several conclusions can be drawn to describe relationships between the AD event and PM distribution characteristics. First of all, it is apparent that the concentrations of PM are distinctively distinguished between AD and NAD. If the extent of contribution to the AD events are assessed on the quantitative basis, it appears that their magnitude increases on the order of PM2.5, PM10, and TSP. As a result, the increase of PM observed during AD event is dominated by the coarse rather than fine fraction of PM. Moreover, when their relationships were assessed in terms of fractional ratios, it was found that TSP/PM10 ratios were almost constant, regardless of the occurrences of AD. On the other hand, the coarse/fine or TSP/PM2.5 ratios changed dramatically between AD and NAD periods. The results of our analysis cleary distinguishes quantitative role of each PM fraction between AD and NAD period, while suggesting indirectly the possible control of source processes on such relationships.