Subcritical Rossby Waves in Zonal Shear Flows with Nonlinear Critical Layers

Autor:	S. A. Maslowe, Simon R Clarke
Rok vydání:	2002
Předmět:	Applied Mathematics Rossby wave Mechanics Supercritical flow Instability Rossby number Nonlinear system symbols.namesake Classical mechanics symbols Wavenumber Rayleigh wave Shear flow Mathematics
Zdroj:	Studies in Applied Mathematics. 108:89-103
ISSN:	1467-9590 0022-2526
DOI:	10.1111/1467-9590.01425
Popis:	It was shown by Benney and Bergeron [1] that singular neutral modes with nonlinear critical layers are mathematically possible in a variety of shear flows. These are usually subcritical modes; i.e., they occur at values of the flow parameters where their linear, viscous counterparts would be damped. One question raised then is how such modes might be generated. This article treats the problem of Rossby waves propagating in a mixing layer with velocity profile ū = tanh y. The beta parameter, which is a measure of the stabilizing Coriolis force, is taken to be large enough so that linear instability cannot occur. First, computed dispersion curves are presented for singular modes with nonlinear critical layers. Then, full numerical simulations are employed to illustrate how these modes can be generated by resonant interaction with conventional nonsingular Rossby waves, even when the singular mode is absent initially.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::a2676742f2fe8e28f36be87a3614a890 https://doi.org/10.1111/1467-9590.01425 Zobrazit plný text záznamu Plný text ve formátu PDF