HR: 09:30h
AN: A51E-06    [Abstracts]
TI: Transboundary Influences on Ozone Pollution in the United States: Present Conditions and Future Projections
AU: Le Sager, P
EM: plesager@seas.harvard.edu
AF: Harvard School of Engineering and Applied Sciences, Pierce Hall 29 Oxford St, Cambridge, MA 02138, United States
AU: * Wang, H
EM: hwang@cfa.harvard.edu
AF: Smithsonian Astrophysical Observatory, MS-50 60 Garden St, Cambridge, MA 02138, United States
AU: Jacob, D J
EM: djacob@fas.harvard.edu
AF: Harvard School of Engineering and Applied Sciences, Pierce Hall 29 Oxford St, Cambridge, MA 02138, United States
AU: Park, R J
EM: rjpark@snu.ac.kr
AF: School of Earth and Environmental Sciences, Seoul National University, San 56-1 Sillim Gwanakgu, Seoul, 151-742, Korea, Republic of
AB: The GEOS-Chem global chemical transport model (v7-02-01) with 1° x1° horizontal resolution over North America is used to investigate the influence of transboundary pollution from Canada and Mexico on surface ozone in the United States. We conduct a series of 4 simulations for present day conditions: (1) a standard simulation with 2001 anthropogenic emissions worldwide, (2) with zero U.S. anthropogenic emissions, (3) with zero anthropogenic emission in North America (Canada, U.S. and Mexico), and (4) with 2006 East Asian emissions and no emission in North America. For future projections, we repeat (1)-(3) with a 2020 worldwide emissions inventory, in addition to a run with U.S. Power plant emissions switched off. The standard simulation is evaluated with observations for U.S. regions most sensitive to transboundary pollution (northeast for Canada, southwest for Mexico). Monthly mean ozone enhancements from transboundary pollution are in the 5-10 ppb range for these regions in June-August, but can exceed 30 ppbv under conditions when ozone is above the U.S. air quality standard (84 ppbv). Unlike intercontinental pollution influence which mainly contributes to the ozone background and is depleted during regional smog episodes, transboundary pollution influence from Canada and Mexico is highly variable and can contribute significantly to these episodes.
DE: 0345 Pollution: urban and regional (0305, 0478, 4251)
DE: 0368 Troposphere: constituent transport and chemistry
SC: Atmospheric Sciences [A]
MN: 2007 Fall Meeting