HR: 10:20h
AN: A32C-01 INVITED     [Abstracts]
TI: Challenges in projecting polar ozone depletion
AU: * Shindell, D T
EM: dshindell@giss.nasa.gov
AF: NASA Goddard Institute for Space Studies, 2880 Broadway, New York, NY 10025 United States
AB: The non-linearity of heterogeneous chemistry in the polar lower stratosphere makes projections of future levels of polar ozone depletion extremely sensitive to temperature changes. Projected trends are therefore quite dependent upon the radiative and dynamical response to climate change in addition to stratospheric halogen loading. The probable course of future halogen loading is considered fairly reliable, and the radiative response to future greenhouse gas abundances is also fairly consistent among models. However, the response of atmospheric dynamics to increased greenhouse gases is more complex. Some aspects of this response are robust, while others vary considerably from model to model. A summary of the results of GCM studies of the response of polar ozone to climate change is presented, highlighting those aspects of future halogen loading, radiative cooling, and chemical modeling that are most uncertain, along with the varied dynamic responses of current models.
DE: 0300 ATMOSPHERIC COMPOSITION AND STRUCTURE
DE: 0340 Middle atmosphere: composition and chemistry
DE: 1610 Atmosphere (0315, 0325)
DE: 3334 Middle atmosphere dynamics (0341, 0342)
DE: 3362 Stratosphere/troposphere interactions
SC: Atmospheric Sciences [A]
MN: Fall Meeting 2005