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On the stability and over-reflexion of hydromagnetic–gravity waves

Published online by Cambridge University Press:  20 April 2006

I. A. Eltayeb
I. A. Eltayeb
Affiliation:
School of Mathematics, The University, Newcastle-upon-Tyne
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Abstract

The stability of a magnetic-velocity shear layer, of thickness L, to hydromagnetic-gravity waves of zonal wavenumber k is investigated analytically, within the Boussinesq approximation, in the situation where ε(= kL) is small. It is found that, in addition to the unstable modes of the corresponding sheet, new modes of instability of growth rate of order ε2 are also present provided one critical level exists within the layer. The existence of one critical level also effects over-reflexion of stable modes. Furthermore it is shown that a magnetic shear acting alone can lead to instability as well as effecting over-reflexion of stable modes.

Type
Research Article
Information
Journal of Fluid Mechanics , Volume 105 , April 1981 , pp. 1 - 18
Copyright
© 1981 Cambridge University Press

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