The project has monitored 2 high air-polluted episodes in central Taiwan. In first episode (from 2006, 5, 5 till 2006, 5, 16), 2 sampling sites of vertical profiles of air pollutants were located in FongYuan City, Taichung County and Nantao City, Taichung County. In second episode (from 2006, 9, 30 till 2006, 10, 6), 2 sampling sites of vertical profiles of air pollutants were located in FongYuan City, Taichung County and Erlin town, Changhua County. The weather patterns observed during two episodes were continental high pressure, frontal zone and outer typhoon circulation. We monitored high PSI values episodes as we expected.
Three weather patterns, continental high pressure, frontal zone and outer typhoon circulation were considered to play important roles in two monitored high PSI values episodes. The monitored results show several patterns of air pollutants. NO2 transformed to O3 during daytime because of photo-chemical reaction, then NOx emmited from mobile sources caused the increase of NO2 concentration. The concentration distribution of TVOCs were higher in mountain area and decreased on the sea, the concentrations variation and accumulation trend of BETX were changed with windfield structure. In Particulate Matters, the average monitored values from Erlin town was the highest, about 1.2~1.4 times the average monitored values of Nantao and FongYuan. PM2.5/PM10 were around 0.51~0.60, showing that fine PM was the main contributor of total PM. The average Fs for FongYuan City were between 0.36~0.41, for Nantao City and Erlin town were around 0.44. The average Fn for FongYuan City, Nantao City and Erlin town were 0.31, 0.17 and 0.13, respectively. It showed that the sources for NOx and SOx in Nantao city were cross-regional transportation.
Ozone simulation used TAPM model in 4 past high PSI episodes between 2004 and 2006. The modeling patterns were close to the observed values. CMB model was used to find the possible sources of the high PSI values, and we conclude that mobile sources are main sources of high PSI episodes, the contribution may be as high as 71%. The possible solution for improving mobile source emissions would be the mass transportation system which is still not well-established in central Taiwan. We also suggest a “turnoff vehicle while waiting or stopping” policy to reduce the unnecessary pollution while vehicles were still. Four local EPBs should also use the communication platform to cooperate in this issue to build a better transportation system, thus encourage people to use it. of four local EPB to
We collected high PSI episodes between 1994 and 2006, and found that 140 days of high PSI episodes out of 225 days companied with typhoons or tropical depression within 2000 km around Taiwan. We employed HYSPLIT anti-trajection model and found that 81 days were affected by typhoons or tropical depression. It indicates that a pre-warning system using weather forecasting method would help the EPB to take proper pre-cautious action before possible high PSI episodes.
One pre-monitoring planning meeting was held, and two examination meetings were held during the project. One website providing the instant information of this project was available for everyone who was interested in this project to find the progress and provide suggestions.
