HR: 0800h
AN: A21E-0780    [Abstracts]
TI: The structure of the Tropical and Extratropical Tropopause Layer: 1960-2100
AU: * Gettelman, A
EM: andrew@ucar.edu
AF: National Center For Atmospheric Research, 1850 Table Mesa Dr, Boulder, CO 80305, United States
AU: Birner, T
EM: thomas@atmosp.physics.utoronto.ca
AF: Department of Physics, University of Toronto 60 George St, Toronto, ON M5S 1A7, Canada
AB: An analysis of the chemical and dynamical structure of the tropical and extratropical tropopause regions from observations and coupled chemistry climate models of the middle atmosphere is presented. The analysis uses detailed results from 2 models and long term simulations from a multi-model ensemble. Models are compared to observations from individual soundings to reanalyses. Variability from daily to interannual time-scales (including the effects of convection and waves) is analyzed. Global models are found to reproduce most scales of variability. Global tropopause trends are examined, including the effects on the UTLS of projected changes to greenhouse gases and halogens (affecting climate and ozone). Models are able to reproduce some aspects of observed trends in tropopause structure in the tropics and extratropics, such as tropopause height trends, but not changes in the meridional extent of the tropics. Future trends in the UTLS to 2100 are explored. Simulations indicate increases in tropopause height and slight increases in tropical tropopause temperature, and increases in the height of convective outflow in the tropical tropopause layer.
DE: 0341 Middle atmosphere: constituent transport and chemistry (3334)
DE: 3337 Global climate models (1626, 4928)
DE: 3362 Stratosphere/troposphere interactions
SC: Atmospheric Sciences [A]
MN: 2007 Fall Meeting