| Summary: | 碩士 === 國立臺灣大學 === 環境工程學研究所 === 89 === This study is to determine the selection criteria for various photochemical indicators based on Taiwan simulation cases, by Taiwan Air Quality Model (TAQM). It also assessed the applicability of indicators.
Studies showed that the indicators selection criteria are influenced by factors such as emission characteristics, meteorology conditions. In this study, the indicator selection criterion was proposed. Eight indicators were investigated based on the summer and autumn cases. The determined criteria ratios are as following: H2O2/HNO3 0.19-0.43; H2O2/NOy 0.082-0.16; H2O2/NOz 0.13-0.19; O3/HNO3 9.7-16; O3/NOy 4.7-9.5; O3/NOz 5.6-8.7; HCHO/NOy 0.29-0.40; NOz/NOy 0.75-0.90.
The consistency of the selection criteria was also investigated, good consistency within the same case was found. However, significant difference was found among different cases. It showed that the selection criteria probably differ with different conditions. NOz/NOy is the only indicator with good consistency, having similar criterion values in all cases. There’s no obvious difference in criteria corresponding to case with difference solar conditions.
H2O2/HNO3, H2O2/NOy and H2O2/NOz have both good performance in accuracy and distinction. O3/HNO3, O3/NOy and O3/NOz have only good accuracy, but poor distinction. HCHO/NOy has good ability of distinction, but its accuracy is poor. There’s no consistency observed among these indicators. Only NOz/NOy has good consistency, however, it has only poor accuracy.
These indicators have different characteristics due to their different theoretical background. The combination of NOz/NOy and indicator will enhance the accuracy significantly.
|
|---|
