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Experiments on buoyant-parcel motion and the generation of internal gravity waves

Published online by Cambridge University Press:  12 April 2006

Carmen P. Cerasoli
Carmen P. Cerasoli
Affiliation:
Geophysical Fluid Dynamics Program, Princeton University, Princeton, New Jersey 08540
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Abstract

Laboratory experiments were conducted to study the motion of miscible buoyant fluid parcels in both homogeneous and stratified media, and were complemented with numerical experiments using the model of Orlanski & Ross (1973). Parcel motion in the homogeneous case was found to be shape-preserving, in agreement with the large body of data for such motion. The stratified medium experiments were such that the parcel attained equilibrium positions. It was found that the time for the parcel to reach maximum depth was approximately 0·7 times the buoyancy period, independent of that depth. The subsequent collapse of the parcel and generation of internal gravity waves was observed. Ray-like patterns of waves propagated out from the collapse region, and wave frequencies near 0·7 times the Brunt-Väisälä frequency were predominant. The internal wave energy radiated away from the collapsed parcel was estimated and found to be 20 to 25% of the change in the system potential energy.

Type
Research Article
Information
Journal of Fluid Mechanics , Volume 86 , Issue 2 , 29 May 1978 , pp. 247 - 271
Copyright
© 1978 Cambridge University Press

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References

Delisi, D. P. & Orlanski, I. 1975 On the role of density jumps in the reflexion and breaking of internal gravity waves. J. Fluid Mech. 69, 445–464.Google Scholar
Escudier, M. P. & Maxworthy, T. 1973 On the motion of turbulent thermals. J. Fluid Mech. 61, 541–552.Google Scholar
Fortuin, J. M. H. 1960 Theory and application of two supplementary methods of constructing density gradient columns. J. Polymer Sci. 44, 505–515.Google Scholar
Kjelaas, A. G., Gossard, E. E., Young, J. M. & Moninger, W. R. 1975 Dispersion and spectra of gravity waves probably generated by a convective storm. Tellus 27, 25–32.Google Scholar
Lilly, D. C. 1962 On the numerical simulation of buoyant convection. Tellus 14, 148–172.Google Scholar
Lilly, D. C. 1964 Numerical solutions for the shape-preserving two-dimensional thermal convection. J. Atmos. Sci. 21, 83–98.Google Scholar
Linden, P. F. 1973 The interaction of a vortex ring with a sharp density interface: a model for turbulent entrainment. J. Fluid Mech. 60, 467–480.Google Scholar
Linden, P. F. 1975 The deepening of a mixed layer in a stratified fluid. J. Fluid Mech. 71, 385–405.Google Scholar
Mclaren, T. I., Pierce, A. D., Fohl, T. & Murphy, B. L. 1973 On investigation of internal gravity waves generated by a buoyantly rising fluid in a stratified medium. J. Fluid Mech. 57, 229–240.Google Scholar
Maxworthy, T. & Browand, F. K. 1975 Experiments in rotating and stratified flows: with oceanographic application. Ann. Rev. Fluid Mech. 7, 273–303.Google Scholar
Morton, B. R., Taylor, G. & Turner, J. S. 1956 Turbulent gravitational convection from maintained and instantaneous sources. Proc. Roy. Soc. A 234, 1–23.Google Scholar
Newton, C. W. 1967 Severe convection storms. Adv. in Geophys. 12, 257–308.Google Scholar
Orlanski, I. & Ross, B. B. 1973 Numerical simulation of the generation and breaking of internal gravity waves. J. Geophys. Res. 78, 8806–8826.Google Scholar
Richards, J. M. 1963 Experiments on the motion of isolated cylindrical thermals through unstratified surroundings. Int. J. Air. Wat. Poll. 7, 17–34.Google Scholar
Scorer, R. S. 1957 Experiments on convection of isolated masses of buoyant fluid. J. Fluid Mech. 2, 583–594.Google Scholar
Scorer, R. S. 1958 Natural Aerodynamics. Pergamon.
Turner, J. S. 1964 The dynamics of spheroidal masses of buoyant fluid. J. Fluid Mech. 19, 481–490.Google Scholar
Wu, J. 1969 Mixed region collapse with internal wave generation in a density stratified medium. J. Fluid Mech. 35, 531–544.Google Scholar
Warren, F. W. G. 1960 Wave resistance to vertical motion in a stratified fluid. J. Fluid Mech. 7, 209–229.Google Scholar