Atmospheric Chemistry and Physics Discussions www.atmos-chem-phys-discuss.net 1680-7367 1680-7375 8 2 2008 10.5194/acpd-8-8059-2008 http://www.atmos-chem-phys-discuss.net/8/8059/2008/ http://www.atmos-chem-phys-discuss.net/8/8059/2008/acpd-8-8059-2008.html http://www.atmos-chem-phys-discuss.net/8/8059/2008/acpd-8-8059-2008.pdf 8059 8090 2008-04-23 Comparison of emission ratios from on-road sources using a mobile laboratory under various driving and operational sampling modes M. Zavala miguelz@mce2.org S. C. Herndon E. C. Wood J. T. Jayne D. D. Nelson A. M. Trimborn E. Dunlea W. B. Knighton A. Mendoza D. T. Allen C. E. Kolb M. J. Molina L. T. Molina Molina Center for the Energy and the Environment, San Diego, California, USA Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA Center for Atmospheric and Environmental Chemistry; Center for Cloud and Aerosol Chemistry, Aerodyne Research Inc., Billerica, Massachusetts, USA Department of Chemistry, Montana State University, Bozeman, Montana, USA Departamento de Ingeniería Química, Tecnológico de Monterrey, Monterrey, México Center for Energy and Environmental Resources, University of Texas, Austin, Texas, USA Dept. of Chemistry and Biochemistry, University of California, San Diego, California, USA now at: National Oceanic and Atmospheric Administration, Climate Program Office, Silver Spring, Maryland, USA Mobile sources produce a significant fraction of the total anthropogenic emissions burden in large cities and have harmful effects on air quality at multiple spatial scales. Mobile emissions are intrinsically difficult to estimate due to the large number of parameters affecting the emissions variability within and across vehicles types. The MCMA-2003 Campaign in Mexico City has showed the utility of using a mobile laboratory to sample and characterize specific classes of motor vehicles to better quantify their emissions characteristics as a function of their driving cycles. The technique clearly identifies "high emitter" vehicles via individual exhaust plumes, and also provides fleet average emission rates. We have applied this technique to Mexicali during the Border Ozone Reduction and Air Quality Improvement Program for the Mexicali-Imperial Valley in 2005. In this paper we analyze the variability of measured emission ratios for emitted NOx, CO, specific VOCs, NH3, and some primary fine particle components and properties obtained during the Border Ozone Reduction and Air Quality Improvement Program for the Mexicali-Imperial Valley in 2005 by deploying a mobile laboratory in roadside stationary sampling, chase and fleet average operational sampling modes. The measurements reflect various driving modes characteristic of the urban fleets. The observed variability for all measured gases and particle emission ratios is greater for the chase and roadside stationary sampling than for fleet average measurements. The fleet average sampling mode captured the effects of traffic conditions on the measured on-road emission ratios, allowing the use of fuel-based emission ratios to assess the validity of traditional "bottom-up" emissions inventories. Using the measured on-road emission ratios, we estimate CO and NOx mobile emissions of 175±62 and 10.4±1.3 metric tons/day, respectively, for the gasoline vehicle fleet in Mexicali. Comparisons with similar on-road emissions data from Mexico City indicated that fleet average NO emission ratios were around 20% higher in Mexicali than in Mexico City whereas HCHO and NH3 emission ratios were higher by a factor of 2 in Mexico City than in Mexicali. Acetaldehyde emission ratios did not differ significantly whereas selected aromatics VOCs emissions were similar or smaller in Mexicali. On-road heavy-duty diesel truck (HDDT) nitrogen oxides emissions were measured near Austin, Texas, as well as in both Mexican cities, with NOy emission ratios in Austin < Mexico City < Mexicali. Cadle, S. H., Ayala, A., Black, K. N., Fulper, C. R., Graze, R. R., Minassian, F., Natarajan, M., Tennant, C. J., and Lawson, D. R.: Real-world vehicle emissions: a summary of the Sixteenth Coordinating Research Council On-Road Vehicle Emissions Workshop, J. Air & Waste Manage. Assoc., 57(2), 139–145, February, 2007. CAM (Comisión Ambiental Metropolitana): Inventario de emisiones 2004 de la Zona Metropolitana del Valle de México, Secretaría del Medio Ambiente, Gobierno de México, México, available at: http://www.sma.df.gob.mx/, 2006. Canagaratna, M. R., Jayne, J. T., Ghertner, D. A., Herndon, S. C., Shi, Q., Jimenez, J. L., Silva, P, J., Williams, P., Lanni, T., Drewnick, F., Demerjian, K. L., Kolb, C. E., Worsnop, D. R.: Chase Studies of Particulate Emissions from in-use New York City Vehicles, Aerosol Science and Technology, 38, 555–573, 2004. CARB (California Air Resources Board): 2006 Almanac emission projection data, available at: http://www.arb.ca.gov/, 2007. Cicero_Fernandez, P., Long, J. R., and Winer, A. M.: Effects of grades and other loads on on-road emissions of hydrocarbons and carbon monoxide, J. Air & Waste Manage. Assoc., 47, 898–904, 1997. Dong, G. and Chan, T. L.: Large eddy simulation of flow structures and pollutant dispersion in the near-wake region of a light-duty diesel vehicle, Atmos. Environ., 40, 1104–1116, 2006. Herndon, S. C., Jayne, J. T., Zahniser, M. S., Worsnop, D. R., Knighton, B., Alwine, E., Lamb, B. K., Zavala, M., Nelson, D. D., McManus, J. B., Shorter, J. H., Canagaratna, M. R., Onasch, T. B., and Kolb, C. E.: Characterization of urban pollutant emission fluxes and ambient concentration distributions using a mobile laboratory with rapid response instrumentation, Faraday Discussions, 130, 327–339, 2005. Herndon, S. C., Shorter, J. H., Zahniser, M. S., Nelson, D. D. J., Jayne, J. T., Brown, R. C., Miake-Lye, R. C., Waitz, I. A., Silva, P., Lanni, T., Demerjian, K. L., Kolb, C. E.: NO and NO2 emission ratios measured from in-use commercial aircraft during taxi and takeoff, Environ. Sci. Technol., 38, 6078–6084, 2004. Jimenez, J. L., Koplow, M. D., Nelson, D. D., Zahniser, M. S., and Schmidt, S. E.: Characterization of on-road vehicle NO emissions by a TILDAS remote sensor, J. Air & Waste Manage. Assoc., 49, 463–470, 1999. Kean, A. J., Harley R. A., and Kendall, G. R.: Effects of vehicle speed and engine load on motor vehicle emissions, Environ. Sci. Technol. 37, 3739–3746, 2003. Kolb, C. E., Herndon, S. C., McManus, J. B., Shorter, J. H., Zahniser, M. S., Nelson, D. D., Jayne, J. T., Canagaratna, M. R., and Worsnop, D. R.: Mobile laboratory with rapid response instruments for real-time measurements of urban and regional trace gas and particulate distributions and emission source characteristics, Environ. Sci. Technol., 38, 5694–5703, 2004. Mendoza, A., Kolb, C., and Russell, A. G.: Mexicali-Imperial valley air quality modeling and monitoring program, final report prepared for LASPAU's Border Ozone Reduction and Air Quality Improvement Program, January, 2007. Molina, L. T., Kolb, C. E., de Foy, B., Lamb, B. K., Brune, W. H., Jimenez, J. L., Ramos-Villegas, R., Sarmiento, J., Paramo-Figueroa, V. H., Cardenas, B., Gutierrez-Avedoy, V., and Molina, M. J.:Air quality in North America's most populous city – overview of the MCMA-2003 campaign, Atmos. Chem. Phys., 7, 2447–2473, 2007. Molina, L. T., Molina, M. J., Slott, R. S., Kolb, C. E., Gbor, P. K., Meng, F., Singh, R. B., Galvez, O., Sloan, J. J., Anderson, W. P., Tang, X. Y., Hu, M., Xie, S., Shao, M., Zhu, T., Zhang, Y. H., Gurjar, B. R., Artaxo, P. E., Oyola, P., Gramsch, E., Hidalgo, D., and Gertler, A. W.: Air quality in selected megacities, critical review complete online version, http://www.awma.org, 2004. NARSTO: Improving emissions inventories for effective air quality management across North America, a NARSTO assessment, NARSTO-05-001, 2005. SEMARNAP: Programa para mejorar la calidad del aire de Mexicali, 2000–2005, Secretaria de Medio Ambiente, Recursos Naturales y Pesca (SEMARNAP), available at: http://www.semarnat.gob.mx/, 1999. Singer, B. C. and Harley, R. A.: A fuel-based inventory of motor vehicle exhaust emissions in the Los Angeles area during summer 1997, Atmos. Environ., 34, 1783–1795, 2000. Wallington, T. J., Kaiser, E. W., and Farrell, J. T.: Automotive fuels and internal combustion engines: achemical perspective, Chemical Society Reviews, 35, 335–347, 2006. Wanga, J. S., Chana,T. L., Cheunga, C. S., Leunga, C. W., and Hung W. T.,: Three-dimensional pollutant concentration dispersion of a vehicular exhaust plume in the real atmosphere, Atmos. Environ., 40, 484–497, 2006. Zavala, M., Herndon, S. C., Slott, R. S., Dunlea, E. J., Marr, L. C., Shorter, J. H., Zahniser, M., Knighton, W. B., Rogers, T. M., Kolb, C. E., Molina, L. T., and Molina, M. J.,: Characterization of on-road vehicle emissions in the Mexico City Metropolitan Area using a mobile laboratory in chase and fleet average measurement modes during the MCMA-2003 field campaign, Atmos. Chem. Phys., 6, 5129–5142., 2006.