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Scattering of internal tides by irregular bathymetry of large extent

Published online by Cambridge University Press:  17 April 2014

Yile Li
Affiliation:
Katy, TX 77450, USA
Chiang C. Mei*
Affiliation:
Department of Civil and Environmental Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
*
Email address for correspondence: ccmei@mit.edu

Abstract

We present an analytical theory of scattering of tide-generated internal gravity waves in a continuously stratified ocean with a randomly rough seabed. Based on a linearized approximation, the idealized case of constant mean sea depth and Brunt–Väisälä frequency is considered. The depth fluctuation is assumed to be a stationary random function of space, characterized by small amplitude and a correlation length comparable to the typical wavelength. For both one- and two-dimensional topographies the effects of scattering on the wave phase over long distances are derived explicitly by the method of multiple scales. For one-dimensional topography, numerical results are compared with Bühler & Holmes-Cerfon (J. Fluid Mech., vol. 678, 2011, pp. 271–293), computed by the method of characteristics. For two-dimensional topography, new results are presented for both statistically isotropic and anisotropic cases.

Type
Papers
Copyright
© 2014 Cambridge University Press 

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References

Abramowitz, M. & Stegun, I. A. 1972 Handbook of Mathematical Functions. Dover.Google Scholar
Alam, M. R. & Mei, C. C. 2007 Attenuation of long interfacial waves over a randomly rough seabed. J. Fluid Mech. 587, 7396.Google Scholar
Alam, M. R. & Mei, C. C. 2008 Ships advancing near the critical speed in a shallow channel with a randomly uneven bed. J. Fluid Mech. 616, 397417.Google Scholar
Arfken, G. B. & Weber, H. J. 2005 Mathematical Methods for Physicists. 6th edn. Harcourt.Google Scholar
Baines, P. G. 1971a The reflextion of internal/inertial waves from bumpy surfaces. J. Fluid Mech. 46, 273294.CrossRefGoogle Scholar
Baines, P. G. 1971b The reflextion of internal/inertial waves from bumpy surfaces. Part 2, Split reflection and diffraction. J. Fluid Mech. 49, 113231.Google Scholar
Baines, P. G. 1973 The generation of internal tides by bumpy topography. Deep-Sea Res. 20, 179205.Google Scholar
Baines, P. G. 1974 The generation of internal tides by steep continental slopes. Phil. Trans. R. Soc. Lond. A 277, 2758.Google Scholar
Baines, P. G. 1982 On internal tide generation models. Deep-Sea Res. 29, 307338.CrossRefGoogle Scholar
Balmforth, N. J., Ierley, G. R. & Young, W. R. 2002 Tidal conversion by subcritical topography. J. Phys. Oceanogr. 32, 29002914.Google Scholar
Balmforth, N. J. & Peacock, T. 2009 Tidal conversion by supercritical topography. J. Phys. Oceanogr. 30, 19651969.CrossRefGoogle Scholar
Bell, T. H. Jr. 1975 Statistical features of seabed topography. Deep-Sea Res. 22, 883892.Google Scholar
Bühler, O. & Holmes-Cerfon, M. 2011 Decay of an internal tide due to random topography in the ocean. J. Fluid Mech. 678, 271293.CrossRefGoogle Scholar
Echeverri, P. & Peacock, T. 2010 Internal tide generation by arbitrary two-dimensional topography. J. Fluid Mech. 659, 247266.CrossRefGoogle Scholar
Goff, J. A. & Jordan, T. H. 1988 Stochastic modelling of seafloor morphology: inversion of sea beam data for second order statistics. J. Geophys. Res. 93 (B11), 1358913608.CrossRefGoogle Scholar
Grataloup, G. & Mei, C. C. 2003 Localization of harmonics generated in nonlinear shallow water waves. Phys. Rev. E 68, 026314.Google Scholar
Hara, T. & Mei, C. C. 1987 Bragg scattering of surface waves by periodic bars: theory and experiment. J. Fluid Mech. 178, 5976.Google Scholar
Llewellyn Smith, S. G. & Young, W. R. 2002 Conversion of the barotropic tide. J. Phys. Oceanogr. 32, 15541566.Google Scholar
Llewellyn Smith, S. G. & Young, W. R. 2003 Tidal conversion at a very steep ridge. J. Fluid Mech. 3495, 171191.Google Scholar
Luz, A. M. & Nachbin, A. 2013 Wave packets defocussing due to a highly disordered bathymetry. Stud. Appl. Maths 130, 393416.Google Scholar
Mei, C. C. 1985 Resonant reflection of surface water waves by periodic sandbars. J. Fluid Mech. 152, 315335.Google Scholar
Mei, C. C. & Hancock, M. J. 2003 Weakly nonlinear surface waves over a random seabed. J. Fluid Mech. 475, 247268.CrossRefGoogle Scholar
Mei, C. C., Hara, T. & Naciri, M. 1988 Note on Bragg scattering of water waves by parallel bars on the seabed. J. Fluid Mech. 186, 147162.Google Scholar
Mei, C. C. & Li, Y. 2004 Evolution of solitons over a randomly rough seabed. Phys. Rev. E 70, 016302.Google Scholar
Mowbray, D. E. & Rarity, B. S. H. 1967 A theoretical and experimental investigation of the phase configuration of internal waves of small amplitude in a density stratified liquid. J. Fluid Mech. 28, 116.CrossRefGoogle Scholar
Muller, P. & Liu, X. 2000 Scattering of internal waves of finite topography in two dimensions, part I: theory and case studies. J. Phys. Oceanogr. 30, 532549.Google Scholar
Muller, P. & Xu, N. 1992 Scattering of oceanic internal gravity waves off random bottom topography. J. Phys. Oceanogr. 22, 474488.Google Scholar
Nachbin, A. 1995 The localization length of randomly scattered water waves. J. Fluid Mech. 296, 353372.Google Scholar
Nikurashin, M. & Ferrari, R. 2010a Radiation and dissipation of internal waves generated by geostrophic motions impinging on small-scale topography: theory. J. Phys. Oceanogr. 40, 10551074.Google Scholar
Nikurashin, M. & Ferrari, R. 2010b Radiation and dissipation of internal waves generated by geostrophic motions impinging on small-scale topography: application to Southern Ocean. J. Phys. Oceanogr. 40, 20252042.Google Scholar
Papoulis, A. 1965 Probability, Random Variables and Stochastic Processes. McGraw-Hill.Google Scholar
Pétrélis, F., Llewellyn Smith, S. G. & Young, W. R. 2006 Tidal conversion at a submarine ridge. J. Phys. Oceanogr. 36, 10531071.Google Scholar
Phillips, O. M. 1966 The Dynamics of the Upper Ocean. Cambridge University Press.Google Scholar
Pihl, J. H., Mei, C. C. & Hancock, M. J. 2002 Surface gravity waves over a two-dimensional random seabed. Phys. Rev. E 66, 016611.Google Scholar
Robinson, R. M. 1969 The effects of a vertical barrier on internal waves. Deep-Sea Res. 16, 421429.Google Scholar
Spanier, J. & Oldham, K. B. 1987 An Atlas of Functions. 2nd edn. Springer.Google Scholar