Effect of the Rainfall during Typhoon Periods on the Variation of Concentration of Ambient Air Pollutants (PM10, NO2, CO, SO2) in the Korean Peninsula

This study has analyzed the concentration variation of four air pollutants (, , CO, and ) during the typhoon periods over 10 years (2002~2011). In this study, 10 typhoon events which had rainfalls in Korean Peninsula were selected during the study period. The analysis was performed using the observation data of both the air pollutants and rainfall. In order to examine and compare the concentrations of the air pollutants between normal periods and typhoon periods, we have obtained monthly average concentrations from July to September and daily average concentrations during typhoon periods. For the period from July to September, 34% of the total rainfalls can be explained by typhoons, and the concentration of air pollutants during the typhoon period was lower than the normal period. In addition, the concentration variations of the pollutants during the typhoon period were analyzed according to two categories: differences in the concentrations between the day before and the day of the typhoon (Case 1) and between the day before and after the typhoon (Case 2). The results indicated that the reduction rate of , , CO, and was 30.1%, 17.9%, 11.6%, 9.7% (Case 1) and 22.8%, 21.0%, 9.0%, 8.0% (Case 2), respectively. This result suggested that air quality was significantly improved during the typhoon period than after the typhoon period by the rainfall.