HR: 1340h
AN: A53C-1352    [Abstracts]
TI: Trans-Pacific Transport of Ozone and Reactive Nitrogen in Spring
AU: * Walker, T W
EM: thomas.walker@dal.ca
AF: Dalhousie University, Department of Physics & Atmospheric Science, Sir James Dunn Building, Halifax, NS B3H 3J5, Canada
AU: Martin, R V
EM: randall.martin@dal.ca
AF: Dalhousie University, Department of Physics & Atmospheric Science, Sir James Dunn Building, Halifax, NS B3H 3J5, Canada
AU: Martin, R V
EM: randall.martin@dal.ca
AF: Harvard-Smithsonian Center for Astrophysics, 60 Garden St, Cambridge, MA 02138, United States
AU: Donkelaar, A v
EM: kelaar@dal.ca
AF: Dalhousie University, Department of Physics & Atmospheric Science, Sir James Dunn Building, Halifax, NS B3H 3J5, Canada
AU: Leaitch, R
EM: richard.leaitch@ec.gc.ca
AF: Environment Canada, 4905 Dufferin Street, Downsview, ON M3H 5T4, Canada
AU: MacDonald, A
EM: annemarie.macdonald@ec.gc.ca
AF: Environment Canada, 4905 Dufferin Street, Downsview, ON M3H 5T4, Canada
AU: Cohen, R C
EM: cohen@cchem.berkeley.edu
AF: University of California at Berkeley, Department of Chemistry, 419 Latimer Hall, UC Berkeley, Berkeley, CA 94720-1460, United States
AU: Huey, G
EM: greg.huey@eas.gatech.edu
AF: Georgia Institute of Technology, School of Earth & Atmospheric Science, Atlanta, GA 30332- 0340, United States
AU: Avery, M A
EM: Melody.A.Avery@nasa.gov
AF: NASA Langley Research Center, 21 Langley Rd, Hampton, VA 23681, United States
AU: Weinheimer, A
EM: wein@acd.ucar.edu
AF: National Center for Atmospheric Research, 1850 Table Mesa Dr., Boulder, CO 80305, United States
AU: Flocke, F
EM: ffl@acd.ucar.edu
AF: National Center for Atmospheric Research, 1850 Table Mesa Dr., Boulder, CO 80305, United States
AU: Tarasick, D
EM: David.Tarasick@ec.gc.ca
AF: Environment Canada, 4905 Dufferin Street, Downsview, ON M3H 5T4, Canada
AU: Thompson, A
EM: anne@met.psu.edu
AF: Penn State University, Department of Meteorology, 503 Walker Building, University Park, PA 16802-5013, United States
AU: Ziemke, J
EM: ziemke@jwocky.gsfc.nasa.gov
AF: University of Maryland Baltimore County, 5523 Research Park Drive, Suite 320, Baltimore, MA 21228, United States
AU: Ziemke, J
EM: ziemke@jwocky.gsfc.nasa.gov
AF: NASA Goddard Space Flight Center, Code 613.3, Greenbelt, MA 20771, United States
AU: Bucsela, E
EM: bucsela@code916.gsfc.nasa.gov
AF: NASA Goddard Space Flight Center, Code 613.3, Greenbelt, MA 20771, United States
AB: We interpret observations from the Intercontinental Chemical Transport Experiment, Phase B (INTEX-B) in spring 2006 using a global chemical transport model (GEOS-Chem) to evaluate sensitivities of the Pacific and North American free troposphere to Asian anthropogenic emissions. Satellite observations of tropospheric NO₂ columns provide timely information on trends in Asian NO_x emissions over 2003-2006 (8.1% yr^-1). We examine ozone and reactive nitrogen measurements from three aircraft platforms from the INTEX-B campaign, including a Canadian Cessna taking vertical profiles of ozone near Whistler Peak. Our baseline simulation reproduces measured ozone and reactive nitrogen profiles with small biases (7% for ozone, 20% for NO_x, and 13% for peroxyacyl nitrates (PN's)). Asian anthropogenic emissions have a mean contribution of > 6.9 ppbv to simulated ozone profiles; lightning NO_x emissions contribute > 3.6 ppbv to ozone profiles on average. Tropospheric ozone columns from the Ozone Monitoring Instrument (OMI) exhibit a broad Asian outflow plume across the Pacific, which is reproduced by simulation. Mean modelled sensitivities of Pacific tropospheric ozone columns to Asian anthropogenic emissions and lightning are > 3.7 Dobson Units (DU) and > 2.1 DU. A sensitivity study decoupling PN's from the model's chemical mechanism establishes that PN's contribute up to 4 ppbv to surface springtime ozone concentrations in western Canada. While ozone production due to PN transport is greatest in the eastern Pacific, persistent winds advect this ozone northeastward into Canada. Transport events observed by the aircraft confirm that airmasses with enhanced PN's (> 500 pptv), ozone (> 95 ppbv), and CO (> 150 ppbv) were advected in this way.
DE: 0345 Pollution: urban and regional (0305, 0478, 4251)
DE: 0365 Troposphere: composition and chemistry
SC: Atmospheric Sciences [A]
MN: 2007 Fall Meeting