LAUSR

ABSTRACT The Taichung Power Plant (TCPP) is the second largest thermal power plant in the world and has been a highly controversial source of PM2.5 emissions. In this study, the CMAQ/MM5 model was validated and used to simulate the PM2.5 levels of the 11 stations in central Taiwan. The Base Case with all emission sources and the Control Case without TCPP emission were simulated. The difference between the two simulated results determines the contribution of TCPP emission. The results showed that most of the daily average contribution was less than 5 μg m-3 at each station in year. However, outlier contribution, representing the extreme episode, could reach to 15 μg m-3 in autumn. Although the maximum annual average contribution of TCPP to a single station was 2.0%, the maximum daily and hourly average contribution could be as high as 17% and 60%, respectively. In most stations, the contribution of the red-grade days (> 54 μg m-3) accounted for less than 10% in a year. The contribution might be underestimated as the temporal variation was not considered particularly in the peak-power operation of summer.