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Chemistry and Biochemistry


Atmospheric chemistry, Emissions, Pollutants


The three California cities of San Jose, Fresno and West Los Angeles (wLA) were visited during March 2008 to collect on-road emission measurements of reactive nitrogen compounds from light-duty vehicles. At the San Jose and wLA sites comparison with historical measurements showed that emissions of carbon monoxide (CO), hydrocarbons (HC) and nitric oxide (NO) continue to decrease in the on-road fleet yet the ratio of nitrogen dioxide (NO2) to NO in new diesel vehicles appears to be under going large increases. A small fleet of 2007 diesel ambulances measured in Fresno was found to have more than 60% of their emitted oxides of nitrogen as NO2. Ammonia (NH3) emissions are shown to have a strong dependence on model year and vehicle specific power. NH3 means of 0.49 ± 0.02, 0.49 ± 0.01 and 0.79 ± 0.02 g/kg of fuel for San Jose, Fresno and wLA, respectively, with the larger emissions at the wLA site likely due to driving mode. NH3 at these locations was found to account for 25%, 22% and 27% of the molar fixed nitrogen emissions. Using these mean values to construct a National fuel based NH3 inventory results in a range of 210,000 to 330,000 short tons of NH3 annually from light-duty vehicles.

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Creative Commons Attribution-NonCommercial 4.0 International License
This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License

Publication Statement

This is an Accepted Manuscript for

Bishop, G. A.; Peddle, A. M.; Stedman, D. H. (2010) On-road Emission Measurements of Reactive Nitrogen compounds from Three California Cities, Environ. Sci. Tech. 54, 14627-14634. DOI: 10.1021/acs.est.0c05433

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Gary A. Bishop, Allison Peddle, Donald H. Stedman


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English (eng)


21 pgs

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195 KB