An Estimate of Tidal Energy Lost to Turbulence at the Hawaiian Ridge

Jody M. Klymak Scripps Institution of Oceanography, La Jolla, California

Search for other papers by Jody M. Klymak in
Current site
Google Scholar
PubMed
Close
,
James N. Moum College of Oceanic and Atmospheric Sciences, Oregon State University, Corvallis, Oregon

Search for other papers by James N. Moum in
Current site
Google Scholar
PubMed
Close
,
Jonathan D. Nash College of Oceanic and Atmospheric Sciences, Oregon State University, Corvallis, Oregon

Search for other papers by Jonathan D. Nash in
Current site
Google Scholar
PubMed
Close
,
Eric Kunze Applied Physics Laboratory, and School of Oceanography, University of Washington, Seattle, Washington

Search for other papers by Eric Kunze in
Current site
Google Scholar
PubMed
Close
,
James B. Girton Applied Physics Laboratory, and School of Oceanography, University of Washington, Seattle, Washington

Search for other papers by James B. Girton in
Current site
Google Scholar
PubMed
Close
,
Glenn S. Carter Applied Physics Laboratory, and School of Oceanography, University of Washington, Seattle, Washington

Search for other papers by Glenn S. Carter in
Current site
Google Scholar
PubMed
Close
,
Craig M. Lee Applied Physics Laboratory, and School of Oceanography, University of Washington, Seattle, Washington

Search for other papers by Craig M. Lee in
Current site
Google Scholar
PubMed
Close
,
Thomas B. Sanford Applied Physics Laboratory, and School of Oceanography, University of Washington, Seattle, Washington

Search for other papers by Thomas B. Sanford in
Current site
Google Scholar
PubMed
Close
, and
Michael C. Gregg Applied Physics Laboratory, and School of Oceanography, University of Washington, Seattle, Washington

Search for other papers by Michael C. Gregg in
Current site
Google Scholar
PubMed
Close
Restricted access

Abstract

An integrated analysis of turbulence observations from four unique instrument platforms obtained over the Hawaiian Ridge leads to an assessment of the vertical, cross-ridge, and along-ridge structure of turbulence dissipation rate and diffusivity. The diffusivity near the seafloor was, on average, 15 times that in the midwater column. At 1000-m depth, the diffusivity atop the ridge was 30 times that 10 km off the ridge, decreasing to background oceanic values by 60 km. A weak (factor of 2) spring–neap variation in dissipation was observed. The observations also suggest a kinematic relationship between the energy in the semidiurnal internal tide (E) and the depth-integrated dissipation (D), such that DE1±0.5 at sites along the ridge. This kinematic relationship is supported by combining a simple knife-edge model to estimate internal tide generation, with wave–wave interaction time scales to estimate dissipation. The along-ridge kinematic relationship and the observed vertical and cross-ridge structures are used to extrapolate the relatively sparse observations along the length of the ridge, giving an estimate of 3 ± 1.5 GW of tidal energy lost to turbulence dissipation within 60 km of the ridge. This is roughly 15% of the energy estimated to be lost from the barotropic tide.

Corresponding author address: J. Klymak, Scripps Institution of Oceanography, 9500 Gilman Dr., Box 0213, La Jolla, CA 92093-0213. Email: jklymak@ucsd.edu

Abstract

An integrated analysis of turbulence observations from four unique instrument platforms obtained over the Hawaiian Ridge leads to an assessment of the vertical, cross-ridge, and along-ridge structure of turbulence dissipation rate and diffusivity. The diffusivity near the seafloor was, on average, 15 times that in the midwater column. At 1000-m depth, the diffusivity atop the ridge was 30 times that 10 km off the ridge, decreasing to background oceanic values by 60 km. A weak (factor of 2) spring–neap variation in dissipation was observed. The observations also suggest a kinematic relationship between the energy in the semidiurnal internal tide (E) and the depth-integrated dissipation (D), such that DE1±0.5 at sites along the ridge. This kinematic relationship is supported by combining a simple knife-edge model to estimate internal tide generation, with wave–wave interaction time scales to estimate dissipation. The along-ridge kinematic relationship and the observed vertical and cross-ridge structures are used to extrapolate the relatively sparse observations along the length of the ridge, giving an estimate of 3 ± 1.5 GW of tidal energy lost to turbulence dissipation within 60 km of the ridge. This is roughly 15% of the energy estimated to be lost from the barotropic tide.

Corresponding author address: J. Klymak, Scripps Institution of Oceanography, 9500 Gilman Dr., Box 0213, La Jolla, CA 92093-0213. Email: jklymak@ucsd.edu

Save
  • Althaus, A. M., E. Kunze, and T. B. Sanford, 2003: Internal tide radiation from Mendocino Escarpment. J. Phys. Oceanogr., 33 , 15101527.

    • Search Google Scholar
    • Export Citation
  • Carter, G. S., and M. C. Gregg, 2002: Intense, variable mixing near the head of Monterey Submarine Canyon. J. Phys. Oceanogr., 32 , 3145.

    • Search Google Scholar
    • Export Citation
  • Carter, G., M. C. Gregg, and M. A. Merrifield, 2006: Flow and mixing around a small seamount on Kaena Ridge, Hawaii. J. Phys. Oceanogr., 36 , 10361052.

    • Search Google Scholar
    • Export Citation
  • Egbert, G. D., and R. D. Ray, 2000: Significant dissipation of tidal energy in the deep ocean inferred from satellite altimeter data. Nature, 405 , 775778.

    • Search Google Scholar
    • Export Citation
  • Finnigan, T., D. Luther, and R. Lukas, 2002: Observations of enhanced diapycnal mixing near the Hawaiian Ridge. J. Phys. Oceanogr., 32 , 29883002.

    • Search Google Scholar
    • Export Citation
  • Ganachaud, A., and C. Wunsch, 2000: Improved estimates of global ocean circulation, heat transport and mixing from hydrographic data. Nature, 408 , 453457.

    • Search Google Scholar
    • Export Citation
  • Gregg, M. C., 1989: Scaling turbulent dissipation in the thermocline. J. Geophys. Res., 94 , 96869698.

  • Henyey, F. S., J. Wright, and S. M. Flatté, 1986: Energy and action flow through the internal wave field. J. Geophys. Res., 91 , 84878495.

    • Search Google Scholar
    • Export Citation
  • Klymak, J. M., and M. C. Gregg, 2004: Tidally generated turbulence over the Knight Inlet sill. J. Phys. Oceanogr., 34 , 11351151.

  • Kunze, E., and J. M. Toole, 1997: Tidally driven vorticity, diurnal shear, and turbulence atop Fieberling Seamount. J. Phys. Oceanogr., 27 , 26632693.

    • Search Google Scholar
    • Export Citation
  • Ledwell, J., A. Watson, and C. Law, 1993: Evidence for slow mixing across the pycnocline from an open-ocean tracer-release experiment. Nature, 364 , 701703.

    • Search Google Scholar
    • Export Citation
  • Lee, C. M., E. Kunze, T. B. Sanford, J. D. Nash, M. A. Merrifield, and P. E. Holloway, 2006: Internal tides and turbulence along the 3000-m isobath of the Hawaiian Ridge. J. Phys. Oceanogr., 36 , 11651183.

    • Search Google Scholar
    • Export Citation
  • Levine, E. R., and R. G. Lueck, 1999: Turbulence measurements with an autonomous underwater vehicle. J. Atmos. Oceanic Technol., 16 , 15331544.

    • Search Google Scholar
    • Export Citation
  • Levine, M. D., and T. J. Boyd, 2006: Tidally forced internal waves and overturns observed on a slope: Results from HOME. J. Phys. Oceanogr., 36 , 11841201.

    • Search Google Scholar
    • Export Citation
  • Llewellyn Smith, S. G., and W. R. Young, 2003: Tidal conversion at a very steep ridge. J. Fluid Mech., 495 , 175191.

  • Marsden, R. F., 1999: A proposal for a neutral regression. J. Atmos. Oceanic Technol., 16 , 876883.

  • Merrifield, M. A., and P. E. Holloway, 2002: Model estimate of M2 internal tide energetics at the Hawaiian Ridge. J. Geophys. Res., 107 .3179, doi:10.1029/2001JC000996.

    • Search Google Scholar
    • Export Citation
  • Moum, J. N., 1996: Energy-containing scales of turbulence in the ocean thermocline. J. Geophys. Res., 101 , 1409514109.

  • Moum, J. N., M. C. Gregg, R. C. Lien, and M. Carr, 1995: Comparison of turbulence kinetic energy dissipation rate estimates from two ocean microstructure profilers. J. Atmos. Oceanic Technol., 12 , 346366.

    • Search Google Scholar
    • Export Citation
  • Moum, J. N., D. R. Caldwell, J. D. Nash, and G. D. Gunderson, 2002: Observations of boundary mixing over the continental slope. J. Phys. Oceanogr., 32 , 21132130.

    • Search Google Scholar
    • Export Citation
  • Munk, W. H., 1966: Abyssal recipes. Deep-Sea Res., 13 , 707730.

  • Munk, W. H., 1981: Internal waves and small-scale processes. Evolution of Physical Oceanography, B. A. Warren and C. Wunsch, Eds., MIT Press, 264–291.

    • Search Google Scholar
    • Export Citation
  • Munk, W., and C. Wunsch, 1998: Abyssal recipes II: Energetics of tidal and wind mixing. Deep-Sea Res., 45 , 19772010.

  • Nash, J. D., E. Kunze, J. M. Toole, and R. W. Schmitt, 2004: Internal tide reflection and turbulent mixing on the continental slope. J. Phys. Oceanogr., 34 , 11171134.

    • Search Google Scholar
    • Export Citation
  • Nash, J. D., M. H. Alford, and E. Kunze, 2005: Estimating internal wave energy fluxes in the ocean. J. Atmos. Oceanic Technol., 22 , 15511570.

    • Search Google Scholar
    • Export Citation
  • Olbers, D. J., 1983: Models of the oceanic internal wave field. Rev. Geophys Space Phys., 21 , 15671606.

  • Osborn, T. R., 1980: Estimates of the local rate of vertical diffusion from dissipation measurements. J. Phys. Oceanogr., 10 , 8389.

  • Polzin, K., 2004: Idealized solutions for the energy balance of the finescale internal wave field. J. Phys. Oceanogr., 34 , 231246.

  • Polzin, K. L., N. S. Oakey, J. M. Toole, and R. W. Schmitt, 1996: Fine structure and microstructure characteristics across the northwest Atlantic subtropical front. J. Geophys. Res., 101 , 1411114121.

    • Search Google Scholar
    • Export Citation
  • Polzin, K., J. Toole, J. Ledwell, and R. Schmitt, 1997: Spatial variability of turbulent mixing in the abyssal ocean. Science, 276 , 9396.

    • Search Google Scholar
    • Export Citation
  • Pomphrey, N., J. D. Meiss, and K. M. Watson, 1980: Description of non-linear inernal wave interactions using Langevin methods. J. Geophys. Res., 85 , 10851094.

    • Search Google Scholar
    • Export Citation
  • Ray, R., and D. Cartwright, 2001: Estimates of internal tide energy fluxes from TOPEX/Poseidon altimetry: Central North Pacific. Geophys. Res. Lett., 28 , 12591262.

    • Search Google Scholar
    • Export Citation
  • Rudnick, D. L., and Coauthors, 2003: From tides to mixing along the Hawaiian Ridge. Science, 301 , 355357.

  • Sanford, T. B., R. G. Drever, and J. H. Dunlap, 1985: An acoustic Doppler and electromagnetic velocity profiler. J. Atmos. Oceanic Technol., 2 , 12541257.

    • Search Google Scholar
    • Export Citation
  • Simmons, H. L., R. W. Hallberg, and B. K. Arbic, 2004: Internal wave generation in a global baroclinic tide model. Deep Sea Res. II, 51 .doi:10.1016/j.dsr2.2004.09.015.

    • Search Google Scholar
    • Export Citation
  • Stigebrandt, A., 1980: Some aspects of tidal interaction with fjord constrictions. Estuar. Coast. Mar. Sci., 11 , 151166.

  • St. Laurent, L., and C. Garrett, 2002: The role of internal tides in mixing the deep ocean. J. Phys. Oceanogr., 32 , 28822899.

  • St. Laurent, L. C., and J. D. Nash, 2004: On the fraction of internal tide energy dissipated near topography. Near-Boundary Processes and Their Parameterization: Proc. ’Aha Huliko’a Hawaiian Winter Workshop, Honolulu, HI, University of Hawaii at Manoa, 45–58.

    • Search Google Scholar
    • Export Citation
  • St. Laurent, L. C., J. M. Toole, and R. W. Schmitt, 2001: Buoyancy forcing by turbulence above rough topography in the abyssal Brazil Basin. J. Phys. Oceanogr., 31 , 34763495.

    • Search Google Scholar
    • Export Citation
  • St. Laurent, L. C., S. Stringer, C. Garrett, and D. Perrault-Joncas, 2003: The generation of internal tides at abrupt topography. Deep Sea Res. I, 50 .doi:10.1016/S0967-0637(03)00096-7.

    • Search Google Scholar
    • Export Citation
  • Wesson, J. C., and M. C. Gregg, 1994: Mixing at Camarinal Sill in the Strait of Gibraltar. J. Geophys. Res., 99 , 98479878.

  • Zaron, E. D., and G. D. Egbert, 2006: Estimating open-ocean barotropic tidal dissipation: The Hawaiian Ridge. J. Phys. Oceanogr., 36 , 10191035.

    • Search Google Scholar
    • Export Citation
All Time Past Year Past 30 Days
Abstract Views 0 0 0
Full Text Views 756 236 33
PDF Downloads 427 114 12