HR: 0800h
AN: A51E-0124 [Abstracts]
TI: Twenty-eight Years of Global Tropospheric Trace Gas Modeling
AU: * Rowland, F
EM: rowland@uci.edu
AF: University of California, Irvine, Department of Chemistry
516 Rowland Hall, Irvine, CA 92697-2025
United States
AU: Simpson, I J
EM: isimpson@uci.edu
AF: University of California, Irvine, Department of Chemistry
516 Rowland Hall, Irvine, CA 92697-2025
United States
AU: Meinardi, S
EM: smeinard@uci.edu
AF: University of California, Irvine, Department of Chemistry
516 Rowland Hall, Irvine, CA 92697-2025
United States
AU: Blake, D R
EM: drblake@uci.edu
AF: University of California, Irvine, Department of Chemistry
516 Rowland Hall, Irvine, CA 92697-2025
United States
AB:
In January 1978 our group began monitoring the global tropospheric concentrations of trace gases that play critical roles in
atmospheric chemistry (CH3CCl3, CFCs, CH4). We have since added numerous other important atmospheric trace
gases to our global monitoring program (CO, CFC replacements, industrial solvents, light alkanes, brominated species, sulfur
species, and organic nitrates). Here we present the long-term atmospheric variations of CH4, CFCs, ethane,
tetrachloroethene (C2Cl4) and other species, with emphasis on variations in northern mid-latitudes. Of particular
interest is the growth rate of atmospheric CH4, which--for the first time in our global monitoring record--has shown
near-zero growth for six years, from 1999-2005. In order to understand better striking fluctuations in methane's annual
growth rate since 1990, we compare the global growth rate of CH4 with those of other OH-controlled species such as
ethane, propane, C2Cl4 and CO. Our results suggest a significant contribution from biomass burning to CH4 and
C2H6 growth rate peaks in 1998 and 2003. We also present new CH3CCl3 measurements from Marseilles and
Milan, which show that substantial emissions of CH3CCl3 have continued in western Europe well past the Montreal
Protocol cut-off date of January 1996.
DE: 0365 Troposphere: composition and chemistry
DE: 0490 Trace gases
DE: 1610 Atmosphere (0315, 0325)
SC: Atmospheric Sciences [A]
MN: Fall Meeting 2005