The Development of Tropopause Folds in Two-Dimensional Models of Frontogenesis

Autor: G. W. Kent Moore
Rok vydání: 1993
Předmět:
Zdroj: Journal of the Atmospheric Sciences. 50:2321-2334
ISSN: 1520-0469
0022-4928
DOI: 10.1175/1520-0469(1993)050<2321:tdotfi>2.0.co;2
Popis: The geostrophic momentum approximation will be employed to investigate the mechanism of tropopause folding that occurs within upper-level fronts formed by the action of a stretching deformation field in a nonuniform potential vorticity fluid. The tropopause, in such a fluid, is represented by a shallow layer in which there is a large change in the potential vorticity. A fold is defined as a region in which the mean tropopause height is a multiple-valued function of the cross-front coordinate. Observational studies have demonstrated that tropopause folds form during frontogenesis as a result of the penetration of stratospheric air down into the troposphere. Earlier studies of this phenomena within the context of semigeostrophic theory have been hampered by the fact that the surface fronts collapse before the upper-level fronts have had a chance to develop. In order to get around this difficulty, previous studies have relied upon unrealistic cross-front temperature gradients, nascent folds, or both...
Databáze: OpenAIRE