Other than the original 3 PE stations which have been in service since 2000 in central Taiwan, two of the AMA stations were deployed in the great Taipei metropolitan area and the rest of the 3 were placed in southern Taiwan in early 2003. Because of the fundamental design differences between PE and AMA, this project has been attempting to craft suitable quality assurance plans for two different systems. The objectives of this project are two fold, first to quality assure all the PAM stations and, secondly, to elucidate the ozone formation mechanism in seasonal high O3 area. After more than 3 years of operation experience the quality assurance plan as well as the standard operation procedure (SOP) have been designed and executed for both the PE and AMA systems. Overall speaking, the stability of the PE systems is superior than that of the AMA systems which lays a good foundation for detailed photochemical studies in central Taiwan. As a result, up to now the photochemical assessment is only based on the data obtained from the network in central Taiwan.This project has developed 2 VOC indicators of the photochemistry with large difference in indication sensitivity. Excellent correlation between ozone and ratios of ethylbenzene/xylene and pentane/t-2-pentene were observed. A quantitative scale was then developed based on first order kinetics to better quantify the degree of aging of an air parcel. Comparison of the air quality stations as well as PAMS in Nantou County revealed that Chushan station can well represent a larger area of Nantou County, with the exception of, perhaps, Puli Township. As a result, we strongly suggest moving Chouton station to Puli in the near future to further analyze the difference in ozone formation mechanism between the great Natou area and Puli Township.

photochemical reaction、ozone precursor