HR: 0800h
AN: A51E-0126    [Abstracts]
TI: Global Budget of C₂H₆ and Constraints on North American Sources From ICARTT Aircraft Data
AU: * Xiao, Y
EM: xyp@io.harvard.edu
AF: Department of Earth and Planetary Sciences & Division of Engineering and Applied Sciences, Harvard University, 29 Oxford Street, Cambridge, MA 02138 United States
AU: Logan, J
EM: jal@io.harvard.edu
AF: Department of Earth and Planetary Sciences & Division of Engineering and Applied Sciences, Harvard University, 29 Oxford Street, Cambridge, MA 02138 United States
AU: Jacob, D
EM: djj@io.harvard.edu
AF: Department of Earth and Planetary Sciences & Division of Engineering and Applied Sciences, Harvard University, 29 Oxford Street, Cambridge, MA 02138 United States
AU: Hudman, R
EM: rch@io.harvard.edu
AF: Department of Earth and Planetary Sciences & Division of Engineering and Applied Sciences, Harvard University, 29 Oxford Street, Cambridge, MA 02138 United States
AU: Blake, D
EM: dblake@orion.oac.uci.edu
AF: University of California,Irvine, Department of Chemistry, Irvine, CA 92697 United States
AB: Atmospheric C₂H₆, with industrial sources similar to those of CH₄ (natural gas recovery and distribution, oil extraction, coal mining), could be an excellent tracer for constraining this portion of the CH₄ budget through observed correlations of C₂H₆-CH₄. Application is limited by uncertainties in the global C₂H₆ budget, with source estimates in the literature ranging from 8 to 36 Tg yr^-1. We use here a global 3-D chemical transport model (GEOS-Chem) to conduct a global budget analysis of atmospheric C₂H₆, evaluating results with surface and aircraft measurements, , and ground-based FTIR observations. With a global source of 13 Tg yr^-1, the model reproduces most of the seasonal and geographical variability found in C₂H₆ observations worldwide. Strong C₂H₆-CO correlations are observed in the aircraft and column data, and these provide additional constraints in the model to separate influences from anthropogenic and biomass burning. Comparison of model results to observations from the ICARTT aircraft mission over eastern North America (July-August 2004) reveals large errors in current U.S. emission inventories for C₂H₆. We apply the model to simulation of the observed C₂H₆-CH₄ correlations from ICARTT to investigate the implications for the North American CH₄ budget.
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
DE: 1704 Atmospheric sciences
SC: Atmospheric Sciences [A]
MN: Fall Meeting 2005