MM5-SMOKE-CMAQ as a modeling tool for 8-h ozone regulatory enforcement: application to the state of Arizona
- 118 Downloads
The Penn State/NCAR Mesoscale Meteorological Model 5 (MM5), Sparse Matrix Operator Kernal Emissions (SMOKE), and Community Multiscale Air Quality (CMAQ) modeling systems were employed to simulate ozone concentration distribution within the State of Arizona, in particular, Phoenix air basin, as supporting information to designate nonattainment areas of the U.S. Environmental Protection Agency's new 8-h ozone standard. In general, based on statistical comparisons between predictions and available (sparsely distributed) observations, the modeling system performed reasonably well for the Phoenix basin, thus proving it to be a useful tool for both regulatory as well as research applications. Detailed inspection, however, revealed a serious problem with respect to the details of the ozone distribution in that for some days the transition from downslope flow to upslope flow in the Phoenix basin was delayed in the model, causing the ozone distribution to show an unrealistic high-ozone bias toward the west valley. Implementation of a modified subgrid parameterization improved the time of transition, and hence the prediction of ozone and its precursor distributions. This study points to possible inadequacies of commonly used subgrid parameterizations in dealing with rapidly changing flow conditions such as morning (and evening) transitions.
Keywords8-h ozone concentration MM5 CMAQ subgrid turbulence parameterization morning transition
Unable to display preview. Download preview PDF.
- 4.Ellis, A. W., Hildebrandt, M. L., & Fernando, H. J. S. (1999). Evidence of lower-atmospheric ozone “Sloshing” in an urbanized valley. Physical Geography, 20, 520–536.Google Scholar
- 5.Ellis, A. W., Hildebrandt, M. L., Thomas, W. M., & Fernando, H. J. S. (2000). Analysis of the climatic mechanisms contributing to the summertime transport of lower atmospheric ozone across metropolitan Phoenix, Arizona, USA. Climate Research, 15, 13–31.Google Scholar
- 10.Lee, S. M., Giori, W., Princevac, M., & Fernando H. J. S. (2006). Implementation of a stable PBL turbulence parameterization for the mesoscale model MM5: Nocturnal flow in complex terrain. Boundary-Layer Meteorology. DOI: 10.1007/s10546-005-9018-4.Google Scholar
- 14.Pielke, R. A., & Pearce, R. P. (1994). Mesoscale modeling of the atmosphere. Meteorological Monographs, 25(47), 156.Google Scholar
- 15.Ricchia, C. (2003). Testimony on behalf of ozone transport commission before the U.S. Environmental Protection Agency on its proposed rule to implement the 8-hour ozone national ambient air quality standard, 6 FR-32, June 7, 2003.Google Scholar