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Breaking of standing internal gravity waves through two-dimensional instabilities

Published online by Cambridge University Press:  26 April 2006

Pascale Bouruet-Aubertot
Affiliation:
Laboratoire de Physique (URA 1325 CNRS), Ecole Normale Supérieure de Lyon, 46 allée d'Italie, 69364 Lyon Cedex 07, France
J. Sommeria
Affiliation:
Laboratoire de Physique (URA 1325 CNRS), Ecole Normale Supérieure de Lyon, 46 allée d'Italie, 69364 Lyon Cedex 07, France
C. Staquet
Affiliation:
Laboratoire de Physique (URA 1325 CNRS), Ecole Normale Supérieure de Lyon, 46 allée d'Italie, 69364 Lyon Cedex 07, France

Abstract

The evolution of an internal gravity wave is investigated by direct numerical computations. We consider the case of a standing wave confined in a bounded (square) domain, a case which can be directly compared with laboratory experiments. A pseudo-spectral method with symmetries is used. We are interested in the inertial dynamics occurring in the limit of large Reynolds numbers, so a fairly high spatial resolution is used (1292 or 2572), but the computations are limited to a two-dimensional vertical plane.

We observe that breaking eventually occurs, whatever the wave amplitude: the energy begins to decrease after a given time because of irreversible transfers of energy towards the dissipative scales. The life time of the coherent wave, before energy dissipation, is found to be proportional to the inverse of the amplitude squared, and we explain this law by a simple theoretical model. The wave breaking itself is preceded by a slow transfer of energy to secondary waves by a mechanism of resonant interactions, and we compare the results with the classical theory of this phenomenon: good agreement is obtained for moderate amplitudes. The nature of the events leading to wave breaking depends on the wave frequency (i.e. on the direction of the wave vector); most of the analysis is restricted to the case of fairly high frequencies.

The maximum growth rate of the inviscid wave instability occurs in the limit of high wavenumbers. We observe that a well-organized secondary plane wave packet is excited. Its frequency is half the frequency of the primary wave, corresponding to an excitation by a parametric instability. The mechanism of selection of this remarkable structure, in the limit of small viscosities, is discussed. Once this secondary wave packet has reached a high amplitude, density overturning occurs, as well as unstable shear layers, leading to a rapid transfer of energy towards dissipative scales. Therefore the condition of strong wave steepness leading to wave breaking is locally attained by the development of a single small-scale parametric instability, rather than a cascade of wave interactions. This fact may be important for modelling the dynamics of an internal wave field.

Type
Research Article
Copyright
© 1995 Cambridge University Press

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References

Auger, F. & Flandrin, P. 1994 Generalization of the reassignment method to all bilinear time-frequency and time scale representations. In Proc. of ICASSP’94 (Int. Conf. on Acoustics, Speech and Signal Processing), 19–22 April 1994, Adelaide Convention Center, Adelaide, South Australia, Vol. IV, pp. 317320.Google Scholar
Bartoloni, A., Battista, C., Cabasino, S., Paolucci, P. S., Pech, J., Sarno, R., Todesco, G. M., Torelli, M., Tross, W. & Vicini, P. 1993 LBE simulations of Rayleigh-Benard convection on the APE100 parallel processor. J. Mod. Phys. C 4, 993.Google Scholar
Bender, C. M. & Orszag, S. A. 1978 Advanced Mathematical Methods for Scientists and Engineers. McGraw-Hill.Google Scholar
Benielli, D. & Sommeria, J. 1994 Excitation of internal waves and stratified turbulence by parametric instability. Submitted to Dyn. Atmos. Oceans (Special Issue 4th Intl Symp. on Stratified Flows (ed. E. J. Hopfinger and B. Voisin)).Google Scholar
Bouruet-Aubertot, P. 1994 Instabilités et déferlement d'ondes internes de gravité. Thèse de doctorat, Université de Lyon.Google Scholar
Bouruet-Aubertot, P., Sommeria, J. & Staquet, C. 1994 Stratified turbulence produced by internal wave breaking. Submitted to Dyn. Atmos. Oceans (Special Issue 4th Intl Symp. on Stratified Flows (ed. E. J. Hopfinger & B. Voisin).Google Scholar
Brachet, M. E. & Meneguzzi, M. & Politano, H. & Sulem, P. L. 1988 The dynamics of freely decaying two-dimensional turbulence. J. Fluid Mech. 194, 333349.Google Scholar
Canuto, C., Hussaini, M. Y., Quateroni, A. & Zang, T. A. 1988 Spectral Methods in Fluid Dynamics. Springer.CrossRefGoogle Scholar
Christie, S. L. & Domaradzki, J. A. 1992 Numerical evidence for nonuniversality of the soft/hard turbulence classification for thermal convection. Phys. Fluids A 5(2) 412421.CrossRefGoogle Scholar
Davis, R. E. & Acrivos, A. 1967 The stability of oscillatory internal waves. J. Fluid Mech. 30, 723736.Google Scholar
Deardorff, J. W. 1965. Gravitational instability between horizontal plates with shear. Phys. Fluids, 8, 10271030.Google Scholar
DeLuca, E. E., Werne, J., Rosner, R. & Cattaneo, F. 1990 Numerical simulations of soft and hard turbulence: preliminary results for two-dimensional convection. Phys. Rev. Lett. 64, 23702373.Google Scholar
Drazin, P. G. 1977 On the instability of an internal gravity wave. Proc. R. Soc. Lond. A 356, 411432.Google Scholar
Drazin, P. G. & Reid, W. H. 1981. Hydrodynamic Stability, Cambridge University Press.Google Scholar
Hasselmann, K. 1962a On the non-linear energy transfer in a gravity wave spectrum. Part 1. J. Fluid Mech. 12, 481500.Google Scholar
Hasselmann, K. 1962b On the non-linear energy transfer in a gravity wave spectrum. Part 2. J. Fluid Mech. 15, 273281.Google Scholar
Hasselmann, K. 1967 A criterion for nonlinear wave stability. J. Fluid Mech. 30, 737739.Google Scholar
Klostermeyer, J. 1982 On parametric instabilities of finite-amplitude internal gravity waves. J. Fluid Mech. 119, 367377.Google Scholar
Klostermeyer, J. 1983 Parametric instability of internal gravity waves in Boussinesq fluids with large Reynolds numbers. Geophys. Astrophys. Fluid Dyn. 26, 85105.Google Scholar
Klostermeyer, J. 1990 On the role of parametric instability of internal gravity waves in atmospheric radar observations. Radio Sci. 25, 983985.Google Scholar
Klostermeyer, J. 1991 Two and three-dimensional parametric instabilities in finite amplitude internal gravity waves. Geophys. Astrophys. Fluid Dyn. 61, 1.Google Scholar
Kraichnan, R. H. & Montgomery, D. 1980 Two-dimensional turbulence, Rep. Prog. Phys. 43, 547617.Google Scholar
Kunze, E. & Williams, A. J. & Briscoe, M.G. 1990 Observations of shear and vertical stability from a neutrally buoyant float. J. Geophys. Res. 95, 127141.Google Scholar
McEwan, A. D. 1971 Degeneration of resonantly-excited standing internal gravity waves. J. Fluid Mech. 50, 431448.Google Scholar
McEwan, A. D. 1983 Internal mixing in stratified fluids. J. Fluid Mech. 128, 5980.Google Scholar
McEwan, A. D., Mander, D. W. & Smith, R. K. 1972 Forced resonant second-order interactions between damped internal waves. J. Fluid Mech. 55, 589608.Google Scholar
McEwan, A. D. & Plumb, R. A. 1977 Off-resonant amplification of finite internal wave packets. Dyn. Atmos. Oceans, 2, 83105.Google Scholar
McEwan, A. D. & Robinson, R. M. 1975 Parametric instability of internal gravity waves. J. Fluid Mech. 67, 667687.Google Scholar
Mied, R. P. 1976 The occurrence of parametric instabilities in finite-amplitude internal gravity waves. J. Fluid Mech. 78, 763784.Google Scholar
Muller, P., Holloway, G., Henyey, F. & Pomphrey, N. 1986 Non linear interactions among internal gravity waves. Rev. Geophys. 24, 493536.Google Scholar
Orlanski, I. 1972 On the breaking of standing internal waves. J. Fluid Mech. 54, 577598.Google Scholar
Orlanski, I. & Bryan, K. 1969 Formation of the thermocline step structure by large-amplitude internal gravity waves. J. Geophys. Res. 74, 69756983.Google Scholar
Orlanski, I. & Cerasoli, C. P. 1980 Resonant and non-resonant wave-wave interactions for internal gravity waves. Marine Turbulence, Proc. 11th Int. Colloquium on Ocean Hydrodynamics, pp. 65100.Google Scholar
Orlanski, I. & Ross, B. B. 1973 Numerical simulations of the generation and breaking of internal gravity waves. J. Geophys. Res. 78, 88088826.Google Scholar
Phillips, O. M. 1960 On the dynamics of unsteady gravity waves of finite amplitude. Part 1. J. Fluid Mech. 9, 193217.Google Scholar
Phillips, O. M. 1961 On the dynamics of unsteady gravity waves of finite amplitude. Part 2. J. Fluid Mech. 11, 143155.Google Scholar
Sekerzh-Zen'covich, S. Ya. 1983 Parametric resonance in a stratified liquid undergoing vertical vibrations. Sov. Phys. Dokl. 28, 445446.Google Scholar
Staquet, C. 1991 Influence of a shear on a stably-stratified flow. In Turbulence and Coherent Structures (ed. O. Metais, and M. Lesieur). Kluwer.CrossRefGoogle Scholar
Taylor, J. R. 1992 The energetics of breaking events in a resonantly forced internal wave field. J. Fluid Mech. 239, 309340.Google Scholar
Thorpe, S. A. 1968 On standing internal gravity waves of finite amplitude. J. Fluid Mech. 32, 489528.Google Scholar
Thorpe, S. A. 1994a The stability of statically unstable layers. J. Fluid Mech. 260, 315331.Google Scholar
Thorpe, S. A. 1994b Statically unstable layers produced by overturning internal gravity waves. J. Fluid Mech. 260, 333350.Google Scholar
Thorpe, S. A. 1994c Observations of parametric instability and breaking waves in an oscillating tilted tube. J. Fluid Mech. 261, 3345CrossRefGoogle Scholar
Winters, K. B. & D'Asaro, E. A. 1989 Two-dimensional instability of finite amplitude internal gravity wave packets near a critical level. J. Geophys. Res. 94, 1270912719.Google Scholar
Winters, K. B. & Riley, J. J. 1992 Instability of internal waves near a critical level. Dyn. Atmos. Oceans 16, 249278.Google Scholar