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Internal gravity waves in a time-varying stratification

Published online by Cambridge University Press:  12 April 2006

Richard Rotunno
Affiliation:
Geophysical Fluid Dynamics Program, Princeton University, Princeton, New Jersey 08540
Present address: National Center for Atmospheric Research, Boulder, Colorado 80307.

Abstract

The influence of slow time variations of the Brun-Väisälä frequency N upon the energy of internal gravity waves is investigated. It is found that, when time variations in N are produced by a mean deformation field (reversible mean state), the wave energy can vary in either direct or inverse proportion, depending on the wavenumber orientation. When N changes owing to a certain type of irreversible process, the wave energy varies with only inverse proportionality.

The nocturnal planetary boundary layer (NPBL) provides an example where N = N(z, t). The full initial/boundary-value problem for an N(z, t) similar to the climatological mean for the NPBL is solved.

Type
Research Article
Copyright
© 1977 Cambridge University Press

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