HR: 0800h
AN: A21E-0777    [Abstracts]
TI: The Spontaneous Formation of a Tropopause Inversion Layer in Simple, Dry, Atmospheric General Circulation Models
AU: * Polvani, L M
EM: lmp@columbia.edu
AF: Columbia University, Department of Applied Physics and Applied Mathematics, New York, NY 10027, United States
AU: Son, S
EM: sws2122@columbia.edu
AF: Columbia University, Department of Applied Physics and Applied Mathematics, New York, NY 10027, United States
AB: The key factors contributing to the formation and maintenance of the recently discovered extra-tropical tropopause inversion layer are presently unclear. In this study, it is shown that such a layer can form as a consequence of the turbulent dynamics of synoptic-scale baroclinic eddies alone, in the absence of explicitly parameterized, small-scale, radiative-convective processes. A simple general circulation model, initialized from a state of rest, and driven with idealized forcings, is found to spontaneously develop an inversion layer above the tropopause under a wide variety of parameter choices and model resolutions. Furthermore, such a model is able to capture, qualitatively, both the latitudinal and (in part) the seasonal dependence of the observed tropopause inversion layer. However, the inability of our simple model to capture some detailed quantitative features strongly suggestes that other physical processes, beyond balanced synoptic-scale dynamics, are likely to play an important role.
UR: http://www.columbia.edu/~lmp/pubs.html DE: 3334 Middle atmosphere dynamics (0341, 0342)
DE: 3337 Global climate models (1626, 4928)
DE: 3362 Stratosphere/troposphere interactions
DE: 3364 Synoptic-scale meteorology
SC: Atmospheric Sciences [A]
MN: 2007 Fall Meeting