HR: 11:35h
AN: A42A-06    [Abstracts]
TI: Model Sensitivity Analysis of Ozone to Mobile Emissions in the MCMA
AU: * Zavala, M
EM: miguelz@mit.edu
AF: Massachussetts Institute of Technology, 77 Mass. Av., Cambridge, MA 02139, United States
AU: * Zavala, M
EM: miguelz@mit.edu
AF: Molina Center for Energy and the Environment, 3262 Holiday Court, Suite 201, La Jolla, CA 92037, United States
AU: Lei, W
AF: Massachussetts Institute of Technology, 77 Mass. Av., Cambridge, MA 02139, United States
AU: Lei, W
AF: Molina Center for Energy and the Environment, 3262 Holiday Court, Suite 201, La Jolla, CA 92037, United States
AU: Herndon, S
AF: Aerodyne Research, Inc., 45 Manning Road, Billerica, MA 01821, United States
AU: Wood, E
AF: Aerodyne Research, Inc., 45 Manning Road, Billerica, MA 01821, United States
AU: Knighton, B
AF: Montana State University, Department of Chemistry & Biochemistry 108 Gaines Hall, Bozeman, MT 59717, United States
AU: Molina, M J
AF: University of California, San Diego, Department of Chemistry and Biochemistry 2040 Urey Hall, La Jolla, CA 92093, United States
AU: Kolb, C E
AF: Aerodyne Research, Inc., 45 Manning Road, Billerica, MA 01821, United States
AU: Molina, L T
AF: Massachussetts Institute of Technology, 77 Mass. Av., Cambridge, MA 02139, United States
AU: Molina, L T
AF: Molina Center for Energy and the Environment, 3262 Holiday Court, Suite 201, La Jolla, CA 92037, United States
AB: Studies of the impacts of air pollution in urban areas with chemical transport models require detailed information on the properties of emitted gases and particles. Moreover, the evaluation of the accuracy of predictions from complex models relies on the quantification of the uncertainties in the main model parameters, and emissions in particular. During the 2002/2003 MCMA and the MCMA-2006/MILAGRO field campaigns in the Mexico City Metropolitan Area (see http:www.mce2.org), the Aerodyne Research Inc. (ARI) Mobile Laboratory characterized on-road vehicle fleet emission indices in fleet-average mode for various vehicle classes using fast-response instrumentation. The measurements obtained by ARI and other groups have been used to validate the emissions inventory in Mexico City and to quantify the uncertainties of emissions as inputs to photochemical models. In this study we perform a sensitivity analysis of the ozone levels predicted from the chemical transport model CAMx to mobile sources by perturbing the base-case scenario of NO_X and VOC emissions. Using the Decoupled Direct Method (DDM) in CAMx, we evaluate the model sensitivity coefficients of ozone to its precursors from mobile sources as well as for other emission sources. The sensitivity coefficients obtained with the DDM method are evaluated against the Brute Force Method (BFM). The predicted ozone changes from the sensitivity analysis are compared with observed historical trends of ozone levels resulting from perturbations on the mobile emission sources.
DE: 0305 Aerosols and particles (0345, 4801, 4906)
DE: 0365 Troposphere: composition and chemistry
DE: 0368 Troposphere: constituent transport and chemistry
DE: 0478 Pollution: urban, regional and global (0345, 4251)
DE: 4251 Marine pollution (0345, 0478)
SC: Atmospheric Sciences [A]
MN: 2007 Joint Assembly