• Adcock, S. T., , and D. P. Marshall, 2000: Interactions between geostrophic eddies and the mean circulation over large-scale bottom topography. J. Phys. Oceanogr., 30 , 32233238.

    • Search Google Scholar
    • Export Citation
  • Aguilar, D. A., , and B. R. Sutherland, 2006: Internal wave generation from rough topography. Phys. Fluids, 18 .066 603, doi:10.1063/1.2214538.

    • Search Google Scholar
    • Export Citation
  • Arbic, B. K., , and G. R. Flierl, 2004: Baroclinically unstable geostrophic turbulence in the limits of strong and weak bottom Ekman friction: Application to midocean eddies. J. Phys. Oceanogr., 34 , 22572273.

    • Search Google Scholar
    • Export Citation
  • Bretherton, F. B., , and D. Haidvogel, 1976: Two-dimensional turbulence over topography. J. Fluid Mech., 78 , 129154.

  • Chapman, D. C., , and D. B. Haidvogel, 1993: Generation of internal lee waves trapped over a tall isolated seamount. Geophys. Astrophys. Fluid Dyn., 69 , 3354.

    • Search Google Scholar
    • Export Citation
  • Danabasoglu, G., , and J. C. McWilliams, 1995: Sensitivity of the global ocean circulation to parameterizations of mesoscale tracer transports. J. Climate, 8 , 29672987.

    • Search Google Scholar
    • Export Citation
  • Danabasoglu, G., , J. C. McWilliams, , and P. R. Gent, 1994: The role of mesoscale tracer transports in the global ocean circulation. Science, 264 , 11231126.

    • Search Google Scholar
    • Export Citation
  • Dewar, W. K., , and P. D. Killworth, 1995: Do fast gravity waves interact with geostrophic motions? Deep-Sea Res., 42 , 10631081.

  • Gent, P. R., , and J. C. McWilliams, 1990: Isopycnal mixing in ocean circulation models. J. Phys. Oceanogr., 20 , 150155.

  • Gent, P. R., , J. Willebrand, , T. J. McDougall, , and J. C. McWilliams, 1995: Parameterizing eddy-induced tracer transports in ocean circulation models. J. Phys. Oceanogr., 25 , 463474.

    • Search Google Scholar
    • Export Citation
  • Gille, S. T., , M. M. Yale, , and D. T. Sandwell, 2000: Global correlation of mesoscale ocean variability with seafloor roughness. Geophys. Res. Lett., 27 , 12511254.

    • Search Google Scholar
    • Export Citation
  • Gregg, M. C., 1987: Diapycnal mixing in the thermocline: A review. J. Geophys. Res., 92 , 52495286.

  • Griffies, S. M., , R. Pacanowski, , and R. Hallberg, 2000: Spurious diapycnal mixing associated with advection in a Z-coordinate ocean model. Mon. Wea. Rev., 128 , 538564.

    • Search Google Scholar
    • Export Citation
  • Huang, R. X., , and W. Wang, 2003: Gravitational potential energy sinks in the oceans. From Stirring to Mixing in a Stratified Ocean: Proc. ‘Aha Huliko‘a Hawaiian Winter Workshop, Honolulu, HI, University of Hawaii at Manoa, 239–247.

    • Search Google Scholar
    • Export Citation
  • Hughes, C. W., , and B. A. de Cuevas, 2001: Why western boundary currents in realistic oceans are inviscid: A link between form stress and bottom pressure torque. J. Phys. Oceanogr., 31 , 28712885.

    • Search Google Scholar
    • Export Citation
  • Kunze, E., , E. Firing, , J. M. Hummon, , T. K. Chereskin, , and A. M. Thurnherr, 2006: Global abyssal mixing inferred from lowered ADCP shear and CTD strain profiles. J. Phys. Oceanogr., 36 , 15531576.

    • Search Google Scholar
    • Export Citation
  • Ledwell, J. R., , A. J. Watson, , and C. S. Law, 1998: Mixing of a tracer in the pycnocline. J. Geophys. Res., 103 , 2149921529.

  • MacCready, P., , G. Pawlak, , K. Edwards, , and R. McCabe, 2003: Form drag on ocean flows. From Stirring to Mixing in a Stratified Ocean: Proc. ‘Aha Huliko‘a Hawaiian Winter Workshop, Honolulu, HI, University of Hawaii at Manoa, 119–130.

    • Search Google Scholar
    • Export Citation
  • Maximenko, N. A., , B. Bang, , and H. Sasaki, 2005: Observational evidence of alternating zonal jets in the world ocean. Geophys. Res. Lett., 32 .L12607, doi:10.1029/2005GL022728.

    • Search Google Scholar
    • Export Citation
  • McWilliams, J. C., , and I. Yavneh, 1998: Fluctuation growth and instability associated with a singularity of the balance equations. Phys. Fluids, 10 , 25872596.

    • Search Google Scholar
    • Export Citation
  • McWilliams, J. C., , I. Yavneh, , M. J. P. Cullen, , and P. R. Gent, 1998: The breakdown of large-scale flows in rotating, stratified fluids. Phys. Fluids, 10 , 31783184.

    • Search Google Scholar
    • Export Citation
  • McWilliams, J. C., , M. J. Molemaker, , and I. Yavneh, 2001: From stirring to mixing of momentum: Cascades from balanced flows to dissipation in the oceanic interior. Near-Boundary Processes and Their Parameterization: Proc. ‘Aha Huliko‘a Hawaiian Winter Workshop, Honolulu, HI, University of Hawaii at Manoa, 59–66.

    • Search Google Scholar
    • Export Citation
  • Molemaker, M. J., , J. C. McWilliams, , and I. Yavneh, 2000: Instability and equilibration of centrifugally-stable stratified Taylor-Couette flow. Phys. Rev. Lett., 86 , 52705273.

    • Search Google Scholar
    • Export Citation
  • Molemaker, M. J., , J. C. McWilliams, , and I. Yavneh, 2005: Baroclinic instability and loss of balance. J. Phys. Oceanogr., 35 , 15051517.

    • Search Google Scholar
    • Export Citation
  • Naveira Garabato, A. C., , K. L. Polzin, , B. A. King, , K. J. Heywood, , and M. Visbeck, 2004: Widespread intense turbulent mixing in the Southern Ocean. Science, 303 , 210213.

    • Search Google Scholar
    • Export Citation
  • Naveira Garabato, A. C., , D. P. Stevens, , A. J. Watson, , and W. Roether, 2007: Short-circuiting of the overturning circulation in the Antarctic Circumpolar Current. Nature, 447 , 194197.

    • Search Google Scholar
    • Export Citation
  • Pain, C. C., and Coauthors, 2005: Three-dimensional unstructured mesh ocean modelling. Ocean Modell., 10 , 533.

  • Polzin, K. L., , and E. Firing, 1997: Estimates of diapycnal mixing using LADCP and CTD data from 18S. International WOCE Newsletter, No. 29, WOCE International Project Office, Southampton, United Kingdom, 39–42.

    • Search Google Scholar
    • Export Citation
  • Rhines, P. B., 1975: Waves and turbulence on a beta-plane. J. Fluid Mech., 69 , 417443.

  • Richards, K. J., , N. A. Maximenko, , F. O. Bryan, , and H. Sasaki, 2006: Zonal jets in the Pacific Ocean. Geophys. Res. Lett., 33 .L03605, doi:10.1029/2005GL024645.

    • Search Google Scholar
    • Export Citation
  • Roberts, M., , and D. Marshall, 1998: Do we require adiabatic dissipation schemes in eddy-resolving ocean models? J. Phys. Oceanogr., 28 , 20502063.

    • Search Google Scholar
    • Export Citation
  • Salmon, R., 1998: Lectures on Geophysical Fluid Dynamics. Oxford University Press, 400 pp.

  • Scott, R. B., , and F. Wang, 2005: Direct evidence of an oceanic inverse kinetic energy cascade from satellite altimetry. J. Phys. Oceanogr., 35 , 16501666.

    • Search Google Scholar
    • Export Citation
  • Scott, R. B., , and B. K. Arbic, 2007: Spectral energy fluxes in geostrophic turbulence: Implications for ocean energetics. J. Phys. Oceanogr., 37 , 673688.

    • Search Google Scholar
    • Export Citation
  • Shcherbina, A., , L. D. Talley, , E. Firing, , and P. Hacker, 2003: Near-surface frontal zone trapping and deep upward propagation of internal wave energy in the Japan/East Sea. J. Phys. Oceanogr., 33 , 900912.

    • Search Google Scholar
    • Export Citation
  • Sloyan, B. M., 2005: Spatial variability of mixing in the Southern Ocean. Geophys. Res. Lett., 32 .L18603, doi:10.1029/2005GL023568.

  • Tandon, A., , and C. Garrett, 1996: On a recent parameterization of mesoscale eddies. J. Phys. Oceanogr., 26 , 406411.

  • Theiss, J., 2004: Equatorward energy cascade, critical latitude, and the predominance of cyclonic vortices in geostrophic turbulence. J. Phys. Oceanogr., 34 , 16331678.

    • Search Google Scholar
    • Export Citation
  • Treguier, A. M., , and B. L. Hua, 1988: Influence of bottom topography on stratified quasi-geostrophic turbulence in the ocean. Geophys. Astrophys. Fluid Dyn., 43 , 265305.

    • Search Google Scholar
    • Export Citation
  • Visbeck, M., , J. Marshall, , T. Haine, , and M. Spall, 1997: On the specification of eddy transfer coefficients in coarse resolution ocean circulation models. J. Phys. Oceanogr., 27 , 381402.

    • Search Google Scholar
    • Export Citation
  • Walter, M., , C. Mertens, , and M. Rhein, 2005: Mixing estimates from a large-scale hydro-graphic survey in the North Atlantic. Geophys. Res. Lett., 32 .L13605, doi:10.1029/2005GL022471.

    • Search Google Scholar
    • Export Citation
  • Watson, A. J., , and A. C. Naveira Garabato, 2006: The role of Southern Ocean mixing and upwelling in glacial–interglacial atmospheric CO2 change. Tellus, 58B , 7387.

    • Search Google Scholar
    • Export Citation
  • Wunsch, C., 1998: The work done by the wind on the oceanic general circulation. J. Phys. Oceanogr., 28 , 23322340.

  • Wunsch, C., , and R. Ferrari, 2004: Vertical mixing, energy, and the general circulation of the oceans. Annu. Rev. Fluid Mech., 36 , 281314.

    • Search Google Scholar
    • Export Citation
  • Yavneh, I., , J. C. McWilliams, , and M. J. Molemaker, 2001: Non-axisymmetric instability of centrifugally stable, stratified Taylor-Couette flow. J. Fluid Mech., 448 , 121.

    • Search Google Scholar
    • Export Citation
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A Conjecture on the Role of Bottom-Enhanced Diapycnal Mixing in the Parameterization of Geostrophic Eddies

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  • 1 Atmospheric, Oceanic and Planetary Physics, University of Oxford, Oxford, United Kingdom
  • | 2 National Oceanography Centre, Southampton, Southampton, United Kingdom
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Abstract

The parameterization of geostrophic eddies represents a large sink of energy in most ocean models, yet the ultimate fate of this eddy energy in the ocean remains unclear. The authors conjecture that a significant fraction of the eddy energy may be transferred to internal lee waves and oscillations over rough bottom topography, leading to bottom-enhanced diapycnal mixing. A range of circumstantial evidence in support of this conjecture is presented and discussed. The authors further propose a modification to the Gent and McWilliams eddy parameterization to account for the bottom-enhanced diapycnal mixing.

Corresponding author address: David Marshall, Atmospheric, Oceanic and Planetary Physics, Clarendon Laboratory, Parks Road, Oxford, OX1 3PU, United Kingdom. Email: marshall@atm.ox.ac.uk

Abstract

The parameterization of geostrophic eddies represents a large sink of energy in most ocean models, yet the ultimate fate of this eddy energy in the ocean remains unclear. The authors conjecture that a significant fraction of the eddy energy may be transferred to internal lee waves and oscillations over rough bottom topography, leading to bottom-enhanced diapycnal mixing. A range of circumstantial evidence in support of this conjecture is presented and discussed. The authors further propose a modification to the Gent and McWilliams eddy parameterization to account for the bottom-enhanced diapycnal mixing.

Corresponding author address: David Marshall, Atmospheric, Oceanic and Planetary Physics, Clarendon Laboratory, Parks Road, Oxford, OX1 3PU, United Kingdom. Email: marshall@atm.ox.ac.uk

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