HR: 10:50h
AN: A42A-03    [Abstracts]
TI: Characterization of North American Ozone-CO Correlations During the ICARTT Study
AU: * Murray, L T
EM: ltm@io.harvard.edu
AF: Division of Engineering and Applied Sciences, Harvard University, Pierce Hall, 29 Oxford Street, Cambridge, MA 02138 United States
AU: Hudman, R C
EM: rch@io.harvard.edu
AF: Division of Engineering and Applied Sciences, Harvard University, Pierce Hall, 29 Oxford Street, Cambridge, MA 02138 United States
AU: Jacob, D J
EM: djj@io.harvard.edu
AF: Division of Engineering and Applied Sciences, Harvard University, Pierce Hall, 29 Oxford Street, Cambridge, MA 02138 United States
AU: Turquety, S
EM: stu@io.harvard.edu
AF: Division of Engineering and Applied Sciences, Harvard University, Pierce Hall, 29 Oxford Street, Cambridge, MA 02138 United States
AU: Avery, M
EM: Melody.A.Avery@nasa.gov
AF: Langley Research Center, NASA, Chemistry and Dynamics Branch, Hampton, VA 23681 United States
AU: Browell, E
EM: Edward.V.Browell@.nasa.gov
AF: Langley Research Center, NASA, Chemistry and Dynamics Branch, Hampton, VA 23681 United States
AU: Holloway, J
EM: jholloway@al.noaa.gov
AF: Aeronomy Laboratory, NOAA, 1850 Table Mesa Drive, Boulder, CO 80303 United States
AU: Sachse, G W
EM: Glen.W.Sachse@nasa.gov
AF: Langley Research Center, NASA, Chemistry and Dynamics Branch, Hampton, VA 23681 United States
AB: Ozone-CO relationships at North American sites and downwind have been used in past studies as diagnostics of ozone production efficiency and export to the global atmosphere. We use here measurements from the ICARTT aircraft campaign (July - August 2004), including the NASA DC-8 and NOAA WP-3D, as an extensive data set to analyze ozone-CO relationships for different North American regions and outflow pathways, and to achieve a better understanding of the ozone budget over North America and its global implications. The observations are interpreted using a 3-D global chemical transport model (GEOS-CHEM). Simulation of the ICARTT data points to large declines of U.S. anthropogenic CO and NO_x emissions relative to the most recent (NEI99) available inventories, and these need to be factored into the interpretation of ozone-CO relationships. Boundary layer observations over the eastern United States during ICARTT indicate higher ozone production efficiency in the Northeast (ΔO₃/ΔCO = 0.46) than the Southeast (ΔO₃/ΔCO = 0.38), and MidWest (ΔO₃/ΔCO = 0.38). The ΔO3/ΔCO values are higher than reported in the literature (~0.30), reflecting the decline of CO emissions. The apparent lower ozone production efficiency in the Southeast than in the Northeast is surprising and possible explanations will be proposed. North American anthropogenic pollution outflow to the Atlantic has ΔO₃/ΔCO = ~0.49, reflecting further free tropospheric O₃ production from exported NO_x.
DE: 0300 ATMOSPHERIC COMPOSITION AND STRUCTURE
DE: 0322 Constituent sources and sinks
DE: 0365 Troposphere: composition and chemistry
DE: 0368 Troposphere: constituent transport and chemistry
SC: Atmospheric Sciences [A]
MN: Fall Meeting 2005