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Titel |
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 |
VerfasserIn |
M. Zavala, S. C. Herndon, R. S. Slott, E. J. Dunlea, L. C. Marr, J. H. Shorter, M. Zahniser, W. B. Knighton, T. M. Rogers, C. E. Kolb, L. T. Molina, M. J. Molina |
Medientyp |
Artikel
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Sprache |
Englisch
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ISSN |
1680-7316
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Digitales Dokument |
URL |
Erschienen |
In: Atmospheric Chemistry and Physics ; 6, no. 12 ; Nr. 6, no. 12 (2006-11-08), S.5129-5142 |
Datensatznummer |
250004174
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Publikation (Nr.) |
copernicus.org/acp-6-5129-2006.pdf |
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Zusammenfassung |
A mobile laboratory was used to measure on-road vehicle emission ratios
during the MCMA-2003 field campaign held during the spring of 2003 in the
Mexico City Metropolitan Area (MCMA). The measured emission ratios represent
a sample of emissions of in-use vehicles under real world driving
conditions for the MCMA. From the relative amounts of NOx and selected
VOC's sampled, the results indicate that the technique is capable of
differentiating among vehicle categories and fuel type in real world driving
conditions. Emission ratios for NOx, NOy, NH3, H2CO,
CH3CHO, and other selected volatile organic compounds (VOCs) are
presented for chase sampled vehicles in the form of frequency distributions
as well as estimates for the fleet averaged emissions. Our measurements of
emission ratios for both CNG and gasoline powered "colectivos" (public
transportation buses that are intensively used in the MCMA) indicate that
– in a mole per mole basis – have significantly larger NOx and aldehydes
emissions ratios as compared to other sampled vehicles in the MCMA.
Similarly, ratios of selected VOCs and NOy showed a strong dependence
on traffic mode. These results are compared with the vehicle emissions
inventory for the MCMA, other vehicle emissions measurements in the MCMA,
and measurements of on-road emissions in U.S. cities. We estimate NOx
emissions as 100 600±29 200 metric tons per year for light duty
gasoline vehicles in the MCMA for 2003. According to these results, annual
NOx emissions estimated in the emissions inventory for this category
are within the range of our estimated NOx annual emissions. Our
estimates for motor vehicle emissions of benzene, toluene, formaldehyde, and
acetaldehyde in the MCMA indicate these species are present in
concentrations higher than previously reported. The high motor vehicle
aldehyde emissions may have an impact on the photochemistry of urban areas. |
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