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Nonlinear interactions of gravity-capillary waves: Lagrangian theory and effects on the spectrum

Published online by Cambridge University Press:  21 April 2006

Klaartje Van Gastel
Affiliation:
Royal Netherlands Meteorological Institute, PO Box 201, 3730 AE De Bilt, The Netherlands Present address: State University of Utrecht. Mathematical Institute, P.O. Box 80.010, 3508 TA Utrecht, The Netherlands.

Abstract

A weakly nonlinear inviscid theory describing the interactions within a continuous spectrum of gravity-capillary waves is developed. The theory is based on the principle of least action and uses a Lagrangian in wavenumber-time space. Advantages of this approach compared to the method of Valenzuela & Laing (1972) are much simplified mathematics and final equations and validity on a longer timescale. It is shown that much of the development of the spectrum under the influence of nonlinear terms can be understood without actually having to integrate the equations. To this end multiwave space, a new concept comparable with phase space, is introduced. Using multiwave space the magnitude of the nonlinear transfer is estimated and it is shown how the energy goes through the spectrum. Also it is predicted that at fixed wavenumbers, the smallest being 520 m−1, finite peaks will arise in the spectrum. This is confirmed by numerical integrations. From the integrations it is also deduced that nonlinear interactions are at least as important to the development of the spectrum as wind growth. Finally it is shown numerically that the near-Gaussian statistics of the sea surface are unaffected by nonlinear interactions.

Type
Research Article
Copyright
© 1987 Cambridge University Press

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References

AtaktÜrk, S. S. & Katsaros, K. B. 1986 Intrinsic frequency spectra of short gravity-capillary waves obtained from temporal measurements of wave height on a lake. University of Washington.
Banner, M. L. & Phillips, O. M. 1974 On the incipient breaking of small scale waves. J. Fluid Mech. 65, 648656.Google Scholar
Bretherton, F. P. 1964 Resonant interactions between waves. The case of discrete oscillations. J. Fluid Mech. 20, 457479.Google Scholar
Davidson, R. C. 1972 Methods in Nonlinear Plasma Theory. Academic.
Gastel, K. Van 1987 Imaging by X-band radar of bottom topography and internal waves: a nonlinear phenomenon. J. Geophys. Res. (to be published).Google Scholar
Gastel, K. Van, Janssen, P. A. E. M. & Komen, G. J. 1985 On phase velocity and growth rate of wind-induced gravity-capillary waves. J. Fluid Mech. 161, 199216.Google Scholar
Guckenheimer, J. & Holmes, P. 1983 Nonlinear Oscillations, Dynamical Systems, and Bifurcations of Vector Fields. Springer-Verlag (Appl. math. sciences 42.)
Hasselmann, K. 1962 On the non-linear energy transfer in a gravity wave spectrum. Part I. J. Fluid Mech. 12, 481500.Google Scholar
Hasselmann, K. & Hasselmann, S. 1981 A symmetrical method of computing the nonlinear transfer in a gravity wave spectrum. Hamburger Geophysikalische Einzelschriften, A-52.
Henyey, F. S. 1983 Hamiltonian description of stratified fluid dynamics. Phys. Fluids 26, 4047.Google Scholar
Henyey, F. S. & Pomphrey, N. 1982 Canonical (Feynman diagram) versus non-canonical (Stokes expansion) calculation of resonant interaction between surfaces waves. Center for Studies of Nonlinear Dynamics, La Jolla.
Holliday, D. 1977 On nonlinear interactions in a spectrum of inviscid gravity-capillary surface waves. J. Fluid Mech. 83, 737749.Google Scholar
Komen, G. J., Hasselmann, S. & Hasselmann, K. 1984 On the existence of a fully-developed wind-sea spectrum. J. Phys. Oceanogr. 14, 12711285.Google Scholar
Krasil'Nikov, V. A. & Pavlov, V. I.1973 The interaction of random waves on a liquid surface. Izu. Atm. Ocean. Phys. 9, 172177.Google Scholar
Liu, H. T. & Lin, J. T. 1982 On the spectra of high-frequency wind waves. J. Fluid Mech. 123, 165185.Google Scholar
Longuet-Higgins, M. S. 1976 On the nonlinear transfer of energy in the peak of a gravity-wave spectrum: a simplified model. Proc. R. Soc. Lond. A 347, 311328.Google Scholar
Longuet-Higgins, M. S. & Smith, M. D. 1966 An experiment on third-order resonant wave interactions. J. Fluid Mech. 25, 417435.Google Scholar
Luke, J. C. 1967 A variational principle for a fluid with a free surface. J. Fluid Mech. 27, 395397.Google Scholar
Mcgoldrick, L. F. 1970 An experiment on second-order capillary gravity resonant wave interactions. J. Fluid Mech. 40, 251271.Google Scholar
Mcgoldrick, L. F., Phillips, O. M., Huang, M. E. & Hodgson, T. H. 1966 Measurements of third-order resonant wave interactions. J. Fluid Mech. 25, 437456.Google Scholar
Meiss, J. & Watson, K. 1978 Discussion of some weakly nonlinear systems in continuum mechanics. AIP Conf. Proc. vol. 46. American Institute of Physics, NY.
Miles, J. W. 1962 On the generation of surface waves by shear flows. Part 4. J. Fluid Mech. 13, 433448.Google Scholar
Miles, J. W. & Salmon, R. 1985 Weakly dispersive nonlinear gravity waves. J. Fluid Mech: 157, 519531.Google Scholar
Phillips, O. M. 1977 The Dynamics of the Upper Ocean, 2nd edn. Cambridge University Press, Cambridge.
Phillips, O. M. 1984 On the response of short ocean wave components at a fixed wavenumber to ocean current variations. J. Phys. Oceanogr. 14, 14251433.Google Scholar
Plant, W. J. 1979 The gravity-capillary wave interaction applied to wind-generated, shortgravity waves. NRL, Washington DC, rep. 8289.
Plant, W. J. 1980 On the steady-state energy balance of short gravity wave systems. J. Phys. Oceanogr. 10, 13401352.Google Scholar
Shemdin, O. H. 1986 ‘Toward 84/86’ field experiment. Investigation of physics and synthetic aperture radar in ocean remote sensing. Interim Rep. Ocean Sciences Division, Office of the Chief of Naval Research, Arlington, Virginia.
Simmons, W. F. 1969 A variational method for weak resonant wave interactions. Proc. R. Soc. Lond. A 309, 551575.Google Scholar
Stolte, S. 1984 Modulation des kurzwelligen Seegangs durch langwelligen Seegang und Wind. FWG-Bericht 1984–6.
Valenzuela, G. R. 1976 The growth of gravity-capillary waves in a coupled shear flow. J. Fluid Mech. 76, 229250.Google Scholar
Valenzuela, G. R. & Laing, M. B. 1972 Nonlinear energy transfer in gravity-capillary wave spectra, with applications. J. Fluid Mech. 54, 507520.Google Scholar
Whitham, G. B. 1967 Variational methods and applications to water waves. Proc. R. Soc. Lond. A 299, 625.Google Scholar
Willebrand, J. 1975 Energy transport in a nonlinear and inhomogeneous random gravity wave field. J. Fluid Mech. 70, 113126.Google Scholar
Zakharov, V. E. 1968 Stability of periodic waves of finite amplitude on the surface of a deep fluid. Zh. Prikl. Mekh. i Tekh. Fiz. 9, 6894.Google Scholar