12th Conference on Middle Atmosphere

Wednesday, 6 November 2002
Interannual variations in stratospheric tracers
Jun Ma, Johns Hopkins University, Baltimore, MD; and D. W. Waugh, P. Newman, A. R. Douglass, and S. Pawson
The interannual variations in stratospheric tracers (e.g., CH4 and N2O) in a chemical transport model driven by winds from a 35-year climate model simulation are examined. The climate model used was a 2.5x2.0 degree resolution version of the finite-colume general circulation model (FVGCM), with 55 levels between the surface and about 80km. The model was run with no interannual variability in the sea-surface temperatures and sea ice distributions, specified at the lower boundary, or in the specified zonal-mean ozone distribution. Despite the absence of variations in these boundary conditions, there is considerable variabaility in the atmospheric circulation. Year-to-year and decadal variations in the trace gas concentrations are examined, as well as the relationship between these variations and those in the stratospheric circulation (e.g., residual circulation) and tropospheric wave forcing. The variations in CH4 from these simulations are also compared with those observed by HALOE.

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