References

ACP

Atmospheric Chemistry and Physics

ACP

1680-7324

Copernicus GmbH

Göttingen, Germany

10.5194/acp-10-8983-2010

Impact of model resolution on chemical ozone formation in Mexico City: application of the WRF-Chem model

Tie

¹ ² Brasseur

¹ ³ Ying

¹ ⁴

National Center for Atmospheric Research, Boulder, CO, USA

Institute of Earth Environment, CAS, Chinese Academy of Science, China

Climate Service Center, GKSS, Hamburg, Germany

York University, Department of Earth and Atmospheric Science, York University, Toronto, Canada

28 09 2010

10 18 8983 8995

This is an open-access article ditributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

This article is available from http://www.atmos-chem-phys.net/10/8983/2010/acp-10-8983-2010.html

The full text article is available as a PDF file from http://www.atmos-chem-phys.net/10/8983/2010/acp-10-8983-2010.pdf

The resolution of regional chemical/dynamical models has important effects on the calculation of the distributions of air pollutants in urban areas. In this study, the sensitivity of air pollutants and photochemical ozone production to different model resolutions is assessed by applying a regional chemical/dynamical model (version 3 of Weather Research and Forecasting Chemical model – WRF-Chemv3) to the case of Mexico City. The model results with 3, 6, 12, and 24 km resolutions are compared to local surface measurements of CO, NOx, and O3. The study shows that the model resolutions of 3 and 6 km provide reasonable simulations of surface CO, NOx, and O3 concentrations and of diurnal variations. The model tends to underestimate the measurements when the resolution is reduced to 12 km or less. The calculated surface CO, NOx, and O3 concentrations at 24 km resolution are significantly lower than measured values. This study suggests that the ratio of the city size to the threshold resolution is 6 to 1, and that this ratio can be considered as a test value in other urban areas for model resolution setting. There are three major factors related to the effects of model resolution on the calculations of O3 and O3 precursors, including; (1) the calculated meteorological conditions, (2) the spatial distribution for the emissions of ozone precursors, and (3) the non-linearity in the photochemical ozone production. Model studies suggest that, for the calculations of O3 and O3 precursors, spatial resolutions (resulting from different meteorological condition and transport processes) have larger impacts than the effect of the resolution associated with emission inventories. The model shows that, with coarse resolution of emission inventory (24 km) and high resolution for meteorological conditions (6 km), the calculated CO and O3 are considerably improved compared to the results obtained with coarse resolution for both emission inventory and meteorological conditions (24 km). The resolution of the surface emissions has important effects on the calculated concentration fields, but the effects are smaller than those resulting from the model resolution. This study also suggests that the effect of model resolution on O3 precursors leads to important impacts on the photochemical formation of ozone. This results directly from the non-linear relationship between O3 formation and O3 precursor concentrations. Finally, this study suggests that, considering the balance between model performance and required computation time on current computers, the 6 km resolution is an optimal resolution for the calculation of ozone and its precursors in urban areas like Mexico City.

References 1

Brasseur, G., Orlando, J., and Tyndall, G.: Atmospheric Chemistry and Global Change, Oxford University Press, 90–120, 1999.

Cairns M. M. and Corey, J.: An application of the MM5 to modeling high winds in complex terrain: A case study in the eastern Sierra, Western Region Tech. Attachment 98-13, 4 pp., 1998.

Chameides, W. L. and Walker, J.: Time dependent photochemical model for ozone near the ground, J. Geophys. Res., 81, 413–420, 1976.

Colle B. A., Mass, C. F., and Westrick, K. J.: MM5 precipitation verification over the Pacific Northwest during the 1997–99 cool seasons, Weather Forecast., 15, 730–744, 2000.

Crutzen, P. J.: Physical and chemical processes which control the production, destruction, and distribution of ozone and some other chemically active minor constituents, GARP Publications Series, 16, pp. 236–243, 1975.

Davis, J. M. and Speckman, P.: A model for predicting maximum and 8 h average \textitozone in Houston, Atmos. Environ., 33, 2487–2500, 1999.

Fast, D. J., de Foy, B., Caetano, E., Skamarock, W., Tie, X., Coulter, R., Barnard, J., and Wiedinmyer, C.: A meteorological overview of the MILAGRO field campaigns, Atmos. Chem. Phys, 7, 2233–2257, doi:10.5194/acp-7-2233-2007, 2007.

Grell, G. A., Peckham, S. E., Schmitz, R., McKeen, S. A., Wilczak, J., and Eder, B.: Fully coupled "online" chemistry within the WRF model, Atmos. Environ., 39, 6957–6975, 2005

Hoadley, J. L., Westrick, K., Ferguson, S. A., Goodrick, S. L., Bradshaw, L., and Werth, P.: The Effect of Model Resolution in Predicting Meteorological Parameters Used in Fire Danger Rating, J. Appl. Meteoro., 43, 1333–1347, 2004.

Kleinman, L. I., Daum, P. H., Imre, D. G., Lee, J. H., Lee, Y.-N., Nunnermacker, L. J., Springston, S. R., Weinstein-Lloyd, J., and Newman, L.: Ozone production in the New York City urban plume, J. Geophys. Res., 105, 14495–14512, doi:10.1029/2000JD900011, 2000.

Lei, W., Zhang, R., Tie, X., and Hess, P.: Chemical characterization of ozone formation in the Houston-Galveston area, J. Geophys. Res., 109, D12301, doi:10.102/2003JD004219, 2004.

Lei, W.,~Zavala, M.,~de~Foy, B.,~Volkamer, R., and~Molina, L T.: Characterizing ozone production and response under different meteorological conditions in Mexico City, Atmos. Chem. Phys.,~8,~7571–7581,~doi:10.5194/acp-8-7581-2008, 2008.

Li., G., Zhang, R., Fan, J., and Tie, X.: Impacts of biogenic emissions on photochemical ozone formation in Houston, Texas, J. Geophys. Res., 112, D10309, doi:10.1029/2006JD007924, 2007.

Lin, X., Trainer, M., and Liu, S. C.: On the nonlinearity of the tropospheric ozone production, J. Geophys. Res., 93(D12), 15879–15888, doi:10.1029/88JD03750, 1988.

Mahmud, A., Tyree, M., Cayan, D., Motallebi, N., Kleeman, M., and Michael, J.: Statistical downscaling of climate change impacts on ozone concentrations in California, J. Geophys. Res. 113, D21103, doi:10.1029/2007JD009534, 2008.

Mass C. F., Ovens, D., Westrick, K. J., and Colle, B. A.: Does increasing horizontal resolution produce more skillful forecasts?, Bull. Am. Meteorol. Soc, 83, 407–430, 2002.

Misenis, C. and Zhang, Y.: An examination of sensitivity of WRF/Chem predictions to physical parameterizations, horizontal grid spacing, and nesting options, Atmos. Res., 97, 315–334, 2010.

Molina, L. and Molina, M. (Eds.), Air Quality in the Mexico MegaCity: An Integrated Assessment, Kluwer Academic Publishers, Dordrecht, The Netherlands, 150–180, 2002.

Noyes, P. D., McElwee, M. K., Miller, H. D., Clark, B. W., Van Tiem, L. A., Walcott, K. C., Erwin, K. N., and Levin, E. D.: The toxicology of climate change, Environ. Int., 35, 971–986, 2009.

Sillman, S.: The use of NOy, H2O2, and HNO3 as indicators for ozone-NOx-hydrocarbon sensitivity in urban locations, J. Geophys. Res., 100, 14175–14188, 1995.

Tie, X., Madronich, S., Li, G. H., Ying, Z. M., Zhang, R., Garcia, A., Lee-Taylor, J., and Liu, Y.: Characterizations of chemical oxidants in Mexico City: A regional chemical/dynamical model (WRF-Chem) study, Atmos. Environ., 41, 1989–2008, 2007.

Tie, X., Geng, F. H., Peng, L., Gao, W., and Zhao, C. S.: Measurement and modeling of O3 variability in Shanghai, China; Application of the WRF-Chem model, Atmos. Environ., 43, 4289–4302, 2009a.

Tie, X., Madronich, S., Li, G. H., Ying, Z. M., Weinheimer, A., Apel, E., and Campos, T.: Simulation of Mexico City Plumes during the MIRAGE-Mex Field Campaign Using the WRF-Chem Model, Atmos. Chem. Phys. 9, 4621–4638, doi:10.5194/acp-9-4621-2009,~2009b.

West, J. J., Zavala, M. A., Molina, L. T., Molina, M. J., Martini, F. S., McRae, G. J., Iglesias, G. S., and Colina, J. L.: Modeling ozone photochemistry and evaluation of hydrocarbon emissions in the Mexico City metropolitan area, J. Geophys. Res., 109, D19312, doi:10.1029/2003JD603652, 2004.

Ying, Z. M., X. Tie, and G. H. Li, Sensitivity of ozone concentrations to diurnal variations of surface emissions in Mexico City: A WRF/Chem modeling study, Atmos. Environ, 43, 851–859, 2009.

Zavala, M., Lei, W., Molina, M. J., and Molina, L. T.: Modeled and observed ozone sensitivity to 15 mobile-source emissions in Mexico City, Atmos. Chem. Phys., 9, 39–55, doi:10.5194/acp-9-39-2009, 2009a.

Zavala, M., Herndon, S. C., Wood, E. C., Onasch, T. B., Knighton, W. B., Marr, L. C., Kolb, C. E., and Molina, L. T.: Evaluation of mobile emissions contributions to Mexico City's emissions inventory using on-road and cross-road emission measurements and ambient data, Atmos. Chem. Phys., 9, 6305–6317, doi:10.5194/acp-8-6365-2009, 2009b.

Zhang, R., Lei, W., Tie, X., and Hess, P.: Industrial emissions cause extreme diurnal urban ozone variability, Proc. Natl. Acad. Sci. USA, 101, 6346–6350, 2004.

Zhang, Y., Dubey, M. K., Olsen, S. C., Zheng, J., and Zhang, R.: Comparisons of WRF/Chem simulations in Mexico City with ground-based RAMA measurements during the 2006-MILAGRO, Atmos. Chem. Phys., 9, 3777–3798, doi:10.5194/acp-9-3777-2009, 2009.