Anelastic internal wave reflection and transmission in uniform retrograde shear
| Autor: | Bruce R. Sutherland, Lauren Eberly |
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| Rok vydání: | 2014 |
| Předmět: | |
| Zdroj: | Physics of Fluids. 26:026601 |
| ISSN: | 1089-7666 1070-6631 |
| Popis: | We perform fully nonlinear simulations in two dimensions of a horizontally periodic, vertically localized, anelastic internal wavepacket in order to examine the effects of weak and strong nonlinearity upon wavepackets approaching a reflection level in uniform retrograde shear. Transmission, reflection, and momentum deposition are measured in terms of the horizontal momentum associated with the wave-induced mean flow. These are determined in part as they depend upon the initial wavenumber vector, k=(k,m), which determines the modulational stability (if |m/k| ≳ 0.7) or instability (if |m/k| ≲ 0.7) of moderately large amplitude quasi-monochromatic internal wavepackets. Whether modulationally stable or unstable, the evolution of the wavepacket is determined by the height of the reflection level predicted by linear theory, zr, relative to the height, zΔ, at which weak nonlinearity becomes significant, and the height, zb>zΔ, at which linear theory predicts anelastic waves first overturn in the absence of shear... |
| Databáze: | OpenAIRE |
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