Air quality and human health - Air Pollution Modeling and Its Application - page 466

average, exposure. We estimated that not taking into account the 'traffic' exposure
term in our data set would lead to an underestimation of exposure to NO 2 and
PM10 by 5% and 3%, respectively, and an overestimation of exposure to O 3 by
2%.
References
Galmarini, S., J.-F. Vinuesa et A. Martilli 2007: M odelling the impact of sub-grid scale emission
variability on upper-air concentration. Atmospheric Chemistry and Physics Discussions, 7(4),
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Georgopoulos, G., Wang, S., Vikram, M., Sun, Q., Burke, J., Vedantham, R., McCu rdy, T., and
Ozkaynak, O. 2005: A source-to-dose assessment of population exposure to fine PM and
ozone in Philadelphia, PA, during a summer 1999 episode, Journal of Exposure Analysis
and Environmental Epidemiology, 15, 439-457.
Krol, M. C., Molemaker, M. J. and Guerau de Arellano, J. V. 2000: Effec ts of turbulence and
heterogeneous emissions on photochemically active species in the convective boundary layer,
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Smith, A. 1997: Writte n statement of testimony before U.S. Senate Subcommittee on Clean Air,
Wetlands, Private Property, and Nuclear Safety. Rapport technique, U.S. Government
Printing Office, Washington, D.C.
Valari, M. and Menut, L. 2008: Does incre ase in air quality models resolution bring surface
ozone concentrations closer to reality?, Journal of Atmospheric and Oceanic Technology, 25,
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Vinuesa, J.-F. et J. V.-G. de Arellano 2005: Introducing effective reaction rates to account for
inefficient mixing in the convective boundary layer. 39: 445-461.
4. Questions and Answers
Massimi Cassiani: Do effects of non-linear chemical reactions on averaged
values explain differences in the model with and without the emission scheme?
Answer: Evidently the non-linear chemical transformations is the explanation of
the large difference between ozone concentrations modelled with the usual CTM
calculation and the implementation of the emission scheme. This becomes clear
by the fact that this difference is much smaller for the primary emitted species.
After all, those differences is what the authors were after: so that chemistry is
better represented inside micro-environments where chemical transformations
occur before mixing homogenizes emissions.
Anthony Dore: How does uncertainty in mapping emissions depend on the
resolution on which emissions are mapped and how confident can you be in the
1 km resolution emissions?
Answer: The whole point of the implementation is to minimize uncertainties due
to emissions and meteorological input. We did so by avoiding the deterministic
downscaling to the 1 km scale so that uncertainties of input are not accumulated