HR: 14:55h
AN: A43G-05 [Abstracts]
TI: Contribution of Regional Transport to Ozone Exceedances in Houston and Dallas, Texas
AU: * Kemball-Cook, S
EM: skemball-cook@environcorp.com
AF: Environ, 773 San Marin Drive, Suite 2115, Novato, CA 94998, United States
AU: Nopmongcol, U
EM: unopmongcol@environcorp.com
AF: Environ, 773 San Marin Drive, Suite 2115, Novato, CA 94998, United States
AU: Johnson, J
EM: jjohnson@environcorp.com
AF: Environ, 773 San Marin Drive, Suite 2115, Novato, CA 94998, United States
AU: Tai, E
EM: etai@environcorp.com
AF: Environ, 773 San Marin Drive, Suite 2115, Novato, CA 94998, United States
AU: Yarwood, G
EM: gyarwood@environcorp.com
AF: Environ, 773 San Marin Drive, Suite 2115, Novato, CA 94998, United States
AU: Parrish, D D
EM: David.D.Parrish@noaa.gov
AF: NOAA/ESRL/Chemical Sciences Division, 325 Broadway R/CSD7, Boulder, CO 80305,
United States
AB:
During the TEXAQS and TEXAQS II field experiments, aircraft measured ozone concentrations upwind, across,
and downwind of Houston and Dallas, and the transport contributions to Dallas area ozone were quantified using
the CAMx photochemical grid model. The transport contribution to ozone exceedances in both urban areas was
at least as large as the contribution from local emissions, on average. For example, analysis of a flight over
Dallas on a day that had a significant exceedance showed that the background ozone transported into Dallas
constituted about 73% of the total ozone concentration. The aircraft measurements show that these two major
metropolitan areas can be brought close to exceeding the 8-hour National Ambient Air Quality Standard for ozone
solely from the ozone contribution from regional transport and before any contribution from local sources. The
CAMx Model-predicted ozone concentrations agreed with the measurements on the importance of regional
transport of ozone relative to local ozone formation. These results emphasize the benefits of regional control
strategies, suggesting that local controls may not be sufficient to ensure attainment of the 8-hour ozone standard
in Houston and Dallas.
DE: 0345 Pollution: urban and regional (0305, 0478, 4251)
DE: 0368 Troposphere: constituent transport and chemistry
SC: Atmospheric Sciences [A]
MN: 2007 Fall Meeting