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| Titel |
Generation of gravity waves through inertia critical levels |
| VerfasserIn |
Eric Danioux, Jacques Vanneste |
| Konferenz |
EGU General Assembly 2010
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 12 (2010) |
| Datensatznummer |
250044228
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| Zusammenfassung |
| The study of the instability of a jet in a primitive equations context shows the importance of
inertia critical levels for the generation of gravity waves. These levels exist where the
Doppler-shifted frequency of a wave matches the Coriolis frequency: Ï - kU = f, with Ï
and k the frequency and wavenumber respectively of the wave involved, U the basic state
velocity and f the Coriolis frequency. At these levels, a balanced wave transforms into a
gravity wave, the amplitude of the latter relative to the former being exponentially small in
Rossby number.
The case of a 1D horizontally uniform shear flow (Eady shear) having been rationalized
in the past, we extend the work to the case of a 2D flow with zero Potential Vorticity. This
mechanism could potentially generate strong amplitude gravity waves as the Rossby number
of a turbulent flow is known to increase with the horizontal wavenumber in this
context (Surface Quasi-Geostrophy). First analytical and numerical results will be
shown. |
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