HR: 14:10h
AN: A53F-03    [Abstracts]
TI: North Pacific Marine Tropospheric Ozone Concentrations at the West Coast of North America: Evaluation of Long-Term Trends
AU: * Parrish, D D
EM: David.D.Parrish@noaa.gov
AF: NOAA/ESRL/CSD, 325 Broadway R/CSD7, Boulder, CO 80305-3328, United States
AB: Activity 1 of the WCRP-SPARC and IGBP-IGAC initiative - Atmospheric Chemistry and Climate - comprises a 20- 25 year hindcast of tropospheric ozone and aerosols, This activity intends to address the following questions: Can we understand what has happened with tropospheric chemistry, and in particular ozone and aerosols? Can we replicate the observed changes over the past 20 years? For this activity to be successful, it is critical that the observed changes must be clearly and accurately defined. However, the observational record is not as extensive as would be desired, and some contradictory conclusions have been reached. These issues are particularly acute for the North Pacific region, which lies downwind of the Asian continent with its rapidly increasing emissions of ozone and aerosol precursors. This presentation will review the available data sets that can illuminate temporal trends of the tropospheric ozone concentrations in the marine air entering North America from the North Pacific, with a particular focus on springtime. The derived long-term temporal trends will be examined for confounding effects from North American influences, statistical significance, and consistency across the available data sets. The derived trends will be compared with those observed at the west coast of Europe, an analogous location that receives marine air from the North Atlantic, which is downwind from the large North American emission sources.
DE: 0322 Constituent sources and sinks
DE: 0345 Pollution: urban and regional (0305, 0478, 4251)
DE: 0365 Troposphere: composition and chemistry
DE: 0368 Troposphere: constituent transport and chemistry
DE: 1610 Atmosphere (0315, 0325)
SC: Atmospheric Sciences [A]
MN: 2007 Fall Meeting