Premium
Two‐level primitive‐equation baroclinic instability on an f ‐plane
Author(s) -
Fraedrich Klaus,
Frisius Thomas
Publication year - 2001
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.49712757611
Subject(s) - baroclinity , barotropic fluid , instability , physics , vorticity equation , advection , vortex , vorticity , divergence (linguistics) , classical mechanics , geology , mechanics , thermodynamics , linguistics , philosophy
Baroclinic instability of a two‐level primitive equation model is represented by a dynamical system consisting of the four interacting fields of barotropic and baroclinic vorticity, divergence and temperature. The instability mechanism is illustrated in terms of a positive feedback loop with a succession of tendencies. It occurs at wavelengths longer than the short wave cut‐off, for which vortex stretching prevails over vertical temperature advection. Quasi‐geostrophy reduces the positive feedback loop to the interaction of the barotropic and baroclinic vorticity fields which are diagnostically linked to divergence and temperature by the omega equation and by geostrophy, respectively.