Comparisons of UAM-V and CAMx model performance and responsiveness to emission control scenarios
The Urban Airshed Model Version V (UAM-V) and the Comprehensive Air Quality Model with Extensions (CAMx) have been both broadly used as the modeling tools in a number of Ozone Transport Assessment Group (OTAG) and post OTAG modeling analyses. Several OTAG modeling comparison studies were conducted and results showed that the performance of the CAMx model for ozone in general was similar to that of the UAM-V model. The model responsiveness to emission control scenarios, however, has not been explored. Moreover, the differences of ozone precursor concentrations between the two models have not been fully investigated. The comparisons of the UAM-V and CAMx models in this study not only include the model predictions of ozone and its precursors but also examine the model responsiveness to NO{sub x} emissions control scenarios. Preliminary results show that the findings are in general consistent with those findings by the previous OTAG comparative studies. Additionally, it was found that the UAM-V tends to predict lower nitric acid (HNO{sub 3}) and NO{sub x} but slightly higher VOC and formaldehyde (HCHO) than the CAMx. Comparison of model responsiveness to NO{sub x} emission control scenarios between the two models shows that both models overall respond similarly. There are, however, notable differences in ozone responses between the UAM-V and the CAMx in specific grid cells. This is possibly because of the different plume-in-grid treatments in the two models. Overall, the UAM-V has slightly higher ozone reduction responses to emission control scenarios than the CAMx. This could be due to lower NO{sub x} and HNO{sub 3} concentrations and slightly higher VOC and HCHO concentrations in the UAM-V than those in the CAMx which leads to a slightly more NOx sensitive condition for the UAM-V.
- Research Organization:
- Environmental Protection Agency, Research Triangle Park, NC (US)
- OSTI ID:
- 20002101
- Report Number(s):
- CONF-990608--
- Country of Publication:
- United States
- Language:
- English
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