Hostname: page-component-848d4c4894-8kt4b Total loading time: 0 Render date: 2024-06-19T09:55:07.611Z Has data issue: false hasContentIssue false

Measurements of internal gravity waves in a continuously stratified shear flow

Published online by Cambridge University Press:  21 April 2006

C. Gary Koop
Affiliation:
TRW Space and Technology Group, Redondo Beach, CA 90278, USA
Brian McGee
Affiliation:
TRW Space and Technology Group, Redondo Beach, CA 90278, USA

Abstract

A theoretical wave-action model, based on the work of Grimshaw (1974), is presented which describes broadbanded internal wave motions in a stratified shear flow with the viscous terms included. The model shows that in the neighbourhood of the critical level viscosity can have important effects and can stabilize the flow with respect to convective overturning. The predictions of the model are compared with the results of an experimental study where detailed measurements of the velocity and density fields are made within an internal wave packet propagating through a continuously stratified shear flow. The results show that the model accurately predicts the occurrence or non-occurrence of wave overturning due to interactions with the shear, and provides an accurate description of the structure of the wave-induced density and velocity fluctuations in those regions of the flow where the assumptions of the model are satisfied.

Type
Research Article
Copyright
© 1991 Cambridge University Press

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Bell T.1975 Topographically generated internal waves in the open ocean. J. Geophys. Res. 80, 320.Google Scholar
Bretherton F.1966 The propagation of groups of internal gravity waves in a shear flow Q. J. R. Met. Soc. A 92, 466.Google Scholar
Broutman D.1982 The interaction of short wavelength internal waves with background current. Ph.D. dissertation, Department of Oceanography, University of California San Diego.
Grimshaw R.1974 Internal gravity waves in a slowly-varying dissipative medium. Geophys. Fluid Dyn. 6, 131.Google Scholar
Grimshaw R.1975 Nonlinear internal gravity waves and their interaction with the mean wind. J. Atmos. Sci. 32, 17791793.Google Scholar
Koop G.1981 A preliminary investigation of the interaction of internal gravity waves with a steady shearing motion. J. Fluid Mech. 113, 347386.Google Scholar
Koop, G. & Browand F.1979 Instability and turbulence in a stratified fluid with shear. J. Fluid Mech. 93, 135159.Google Scholar
Mied, R. & Dugan J.1974 Internal gravity wave reflection by a layered density anomaly. J. Phys. Oceanogr. 4, 493498.Google Scholar
Munk W.1980 Internal waves and small scale processes, in Evolution of Physical Oceanography, pp. 264291, MIT Press.
Orlanski, I. & Bryan K.1969 On the formation of the thermocline step structure by large-amplitude internal gravity waves. J. Geophys. Res. 74, 6975.Google Scholar
Thorpe S.1981 An experimental study of critical layers. J. Fluid Mech. 103, 321344.Google Scholar