Model assessment and verification - Air Pollution Modeling and Its Application - page 299

generated by the MOBILE6 model at these locations. Although mobile emissions
represent a majority (≈70% or more) of NO x emissions in the urban areas, variations
in NO x emissions from other source categories are also likely impacting the relative
change in concentrations.
Fig. 4. Results of (a) modeled and (b) observed mean NO x concentrations averaged over the 50th
to 95th percentiles of CFDs for the summer of 2002 versus 2005
Disclaimer Although this work was reviewed by EPA and approved for publication, it may not
necessarily reflect official Agency policy.
References
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Gilliland, A.B., C. Hogrefe, R.W. Pinder, et al., 2008. Dynamic evaluation of regional air quality
models: Assessing changes in O 3 stemming from changes in emissions and meteorology. Atmos.
Environ., 42, 5110-5123.
NESCAUM, 2006. The Nature of the Ozone Air Quality Problem in the North east: A Conceptual
Description. October 2006, Boston, MA. ( http://www.nescaum.org/topics/air-pollution-
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USEPA, 2005. Evaluating Ozone Control Programs in the Eastern United States:Focus on the
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