Premium
A variational theorem for circulation integrals applied to inviscid symmetric flows with variable stability and shear
Author(s) -
Emanuel Kerry A.
Publication year - 1982
Publication title -
quarterly journal of the royal meteorological society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.744
H-Index - 143
eISSN - 1477-870X
pISSN - 0035-9009
DOI - 10.1002/qj.49710845806
Subject(s) - inviscid flow , instability , extratropical cyclone , perturbation (astronomy) , eigenvalues and eigenvectors , mathematics , simple (philosophy) , mathematical analysis , meteorology , physics , classical mechanics , mechanics , quantum mechanics , philosophy , epistemology
Conditional symmetric instability has recently been proposed as an explanation for rain and cloud bands which are imbedded in larger regions of precipitation associated with extratropical cyclones (Bennetts and Hoskins 1979). In their paper, Bennetts and Hoskins discuss the use of a circulation integral for calculating growth rates of the instability. The purpose of this note is to demonstrate that the growth rates so calculated will be exact eigenvalues of the associated linear perturbation equations provided that these growth rates are maximized with respect to the path of integration. A simple application is presented and compared with results of a numerical experiment using the Bennetts and Hoskins model. The circulation integral method appears to be a simple way of assessing the potential for conditional symmetric instability in the atmosphere.