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Original Research Papers

Energetics of tidally generated internal waves for nonuniform stratification

Authors:

Moundheur Zarroug ,

Department of Meteorology, Stockholm University, 106 91 Stockholm, SE
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Jonas Nycander,

Department of Meteorology, Stockholm University, 106 91 Stockholm, SE
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Kristofer Döös

Department of Meteorology, Stockholm University, 106 91 Stockholm, SE
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Abstract

The generation of internal waves from barotropic tides can be quantified in terms of the conversion rates. These have often been obtained by applying the WKB approximation, which yields an expression for the conversion rates which is proportional to the seabed buoyancy frequency NB. For small values of NB or strong variations of the buoyancy profile N(z), this gives unreliable results. Using homogenization theory it is here shown that the conversion rate instead depends on the value of N(z) averaged over a vertical region at the bottom of the same magnitude as the vertical length-scale of the internal wave, which for the lowest modes is of the same order as the entire ocean depth. This gives a substantially larger conversion rate.

How to Cite: Zarroug, M., Nycander, J. and Döös, K., 2010. Energetics of tidally generated internal waves for nonuniform stratification. Tellus A: Dynamic Meteorology and Oceanography, 62(1), pp.71–79. DOI: http://doi.org/10.1111/j.1600-0870.2009.00415.x
12
Citations
  Published on 01 Jan 2010
 Accepted on 14 Aug 2009            Submitted on 16 Feb 2009

References

  1. Alford , M. H . 2003 . Redistribution of the energy available for ocean mixing by long-range propagation of internal waves . Nature 423 , 159 – 162 .  

  2. Andrews , J. C. and Gentien , P . 1982 . Upwelling as a source of nutrients for the Great Barrier Reef ecosystem: a solution to Darwin’s question? Mar EcoL Prog. Ser 8 , 257 – 269 .  

  3. Bell , T. H . 1975a . Lee waves in stratified flows with simple harmonics time dependence . J. Fluid Mech . 67 , 705 – 722 .  

  4. Bell , T. H . 1975b . Topographically generated internal waves in the open ocean . J. Geophys. Res . 80 ( 3 ), 320 – 327 .  

  5. Bender , C. M. and Orszag , S. A . 1978 . Advanced Mathematical Methods for Scientists and Engineers , McGraw-Hill , New York .  

  6. Egbert , G. D. and Ray , R . 2000 . Significant dissipation of tidal energy in the deep ocean inferred from satellite altimeter data . Nature 405 , 775 – 778 .  

  7. Egbert , G. D. and Ray , R . 2001 . Estimates of M2 tidal energy dissipation from TOPEX/POSEIDON altimeter data . J. Geophys. Res . 106 ( C10 ), 22475 – 22502 .  

  8. Khatiwala , S . 2003 . Generation of internal tides in an ocean of finite depth: analytical and numerical calculations . Deep Sea Res . 1 , 50 , 3 – 21 .  

  9. Ledwell , J. R. , Montgomery , E. T. , Polzin , L. T. , St. Laurent , L. C. , Schmitt , R. W. , and co-authors . 2000 . Evidence for enhanced mixing over rough topography in the Abyssal Ocean. Nature 403 , 179 – 182 .  

  10. Leichter , J. J. , Shellenbarger , G. , Genovese , S. J. and Wing , S. R . 1998 . Breaking internal waves on a Florida (USA) coral reef: a plankton pump at work? Mar EcoL Prog. Ser 166 , 83 – 97 .  

  11. Llewellyn Smith , S. G. and Young , W. R . 2002 . Conversion of the Barotropic tide . J. Phys. Oceangr . 32 , 1554 – 1566 .  

  12. Morse , P. and Feshbach , H . 1953 . Methods of Theoretical Physics , McGraw-Hill , New York .  

  13. Munk , W. and Wunsch , C ., 1998 . Abyssal recipes II: energetics of tidal and wind mixing . Deep-Sea Res . 1 , 45 , 1977 – 2010 .  

  14. Nilsson , J. , Brostriim , G. and Walin , G . 2003 . The thermohaline circulation and vertical mixing: does weaker density stratification give stronger overturning? J. Phys. Oceanogr 33 , 2781 – 2795 .  

  15. Nycander , J . 2005 . Generation of internal waves in the deep ocean by tides . J. Geophys. Res . 101 , C10028 , https://doi.org/10.1029/2004JC002487 .  

  16. Sandström , J. W . 1908 . Dynamishe Versuche mit Meerwasser . Annals in Hydrodynamic Marine Meteorology . 36 , 6 – 23 .  

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