Numerical Investigation of the Effects of Boundary-Layer Evolution on the Predictions of Ozone and the Efficacy of Emission Control Options in the Northeastern United States
Document ID: 150
Ku, Jia-Yeong1
Mao, Huiting2
Zhang, Kesu2
Civerolo, Kevin1
Rao, S. Trivikrama1,2
Philbrick, C. Russell3
Doddridge, Bruce G.4
Clark, Richard D.5
1 New York State Department of Environmental Conservation, Albany, NY, U.S.A.
2 University at Albany, Department of Earth and Atmospheric Sciences, Albany, NY, U.S.A.
3 The Pennsylvania State University, Department of Electrical Engineering, University Park, PA, U.S.A.
4 University of Maryland, Department of Meteorology, College Park, MD, U.S.A.
5 Millersville University of Pennsylvani, Department of Earth Sciences, Millersville, PA, U.S.A.
Abstract
Abstract. This paper examines the effects of two different planetary boundary-layer (PBL) parameterization schemes – Blackadar and Gayno–Seaman – on the predicted ozone (O3) concentration fields using the MM5 (Version 3.3) meteorological model and the MODELS-3 photochemical model. The meteorological fields obtained from the two boundary-layer schemes have been used to drive the photochemical model to simulate O3 concentrations in the northeastern United States for a three day O3 episodic period. In addition to large differences in the predicted O3 levels at individual grid cells, the simulated daily maximum 1-h O3 concentrations appear at different regions of the modeling domain in these simulations, due to the differences in the vertical exchange formulations in these two PBL schemes. Using process analysis, we compared the differences between the different simulations in terms of the relative importance of chemical and physical processes to O3 formation and destruction over the diurnal cycle. Finally, examination of the photochemical model’s response to reductions in emissions reveals that the choice of equally valid boundary-layer parameterizations can significantly influence the efficacy of emission control strategies.
Keywords: mixing heights, ozone, photochemical models, planetary boundary-layer