Abstract
The turbulent motions responsible for ocean mixing occur on scales much smaller than those resolved in numerical simulations of oceanic flows. Great progress has been made in understanding the sources of energy for mixing, the mechanisms, and the rates. On the other hand, we still do not have adequate answers to first order questions such as the extent to which the thermohaline circulation of the ocean, and hence the earth's climate, is sensitive to the present mixing rates in the ocean interior. Internal waves, generated by either wind or flow over topography, appear to be the principle cause of mixing. Mean and eddy flows over topography generate internal lee waves, while tidal flows over topography generate internal tides. The relative importance of these different internal wave sources is unknown. There are also great uncertainties about the spatial and temporal variation of mixing. Calculations of internal tide generation are becoming increasingly robust, but we do not know enough about the subsequent behavior of internal tides and their eventual breakdown into turbulence. It does seem, however, that most internal tide energy flux is radiated away from generation sites as low modes that propagate over basin scales. The mechanisms of wave-wave interaction and topographic scattering both act to transfer wave energy from low modes to smaller dissipative scales.
Similar content being viewed by others
References
Alford, M. H. (2001a): Fine-structure contamination: observations and a model of a simple two-wave case. J. Phys. Oceanogr., 31, 2645–2649.
Alford, M. H. (2001b): Internal swell generation: The spatial distribution of energy flux from the wind to mixed-layer near-inertial motions. J. Phys. Oceanogr., 31, 2359–2368.
Armi, L. (1978): Some evidence for boundary mixing in the deep ocean. J. Geophys. Res., 83, 1971–1979.
Baines, P. G. (1973): The generation of internal tides by flat-bump topography. Deep-Sea Res., 20, 179–205.
Baines, P. G. (1982): On internal tide generation models. Deep-Sea Res., 29, 307–338.
Balmforth, N. J., G. R. Ierley and W. R. Young (2001): Tidal conversion by nearly critical topography. J. Phys. Oceanogr. (submitted).
Bell, T. H. (1975a): Lee waves in stratified flows with simple harmonic time dependence. J. Fluid Mech., 67, 705–722.
Bell, T. H. (1975b): Topographically generated internal waves in the open ocean. J. Geophys. Res., 80, 320–327.
Bryan, F. (1987): Parameter sensitivity of primitive equation ocean general circulation models. J. Phys. Oceanogr., 17, 970–985.
Cox, C. S. and H. Sandstrom (1962): Coupling of surface and internal waves in water of variable depth. Journal of the Oceanographic Society of Japan, 20th Anniversary Volume, 499–513.
Craig, P. D. (1987): Solutions for internal tide generation over coastal topography. J. Mar. Res., 45, 83–105.
Cummins, P. F., J. Y. Cherniawski and M. G. G. Foreman (2001): North Pacific internal tides from the Aleutian Ridge: Altimeter observations and modelling. J. Mar. Res., 59, 167–191.
D'Asaro, E. A. (1991): A strategy for investigating and modeling internal wave sources and sinks. p. 451–465. In Dynamics of Oceanic Internal Gravity Waves, Proc. ‘Aha Huliko’ a Hawaiian Winter Workshop, ed. by P. Muller and D. Henderson, SOEST.
Davis, R. E. (1994): Diapycnal mixing in the ocean: Equations for large-scale budgets. J. Phys. Oceanogr., 24, 777–800.
Egbert, G. D. (1997): Tidal data inversion: Interpolation and inference. Prog. Oceanogr., 40, 81–108.
Egbert, G. D. and R. D. Ray (2000): Significant dissipation of tidal energy in the deep ocean inferred from satellite altimeter data. Nature, 405, 775–778.
Egbert, G. D. and R. D. Ray (2001): Estimates of M2 tidal energy dissipation from TOPEX/POSEIDON altimeter data. J. Geophys. Res. (in press).
Egbert, G. D., A. F. Bennett and M. G. G. Foreman (1994): TOPEX/POSEIDON tides estimated using a global inverse model. J. Geophys. Res., 99, 24821–24852.
Eriksen, C. C. (1998): Internal wave reflection and mixing at Fieberling Guyot. J. Geophys. Res., 103, 2977–2994.
Ferron, B., H. Mercier, K. Speer, A. Gargett and K. Polzin (1998): Mixing in the Romanche Fracture Zone. J. Phys. Oceanogr., 28, 1929–1945.
Gargett, A. and J. Marra (2001): Effects of upper ocean physical processes—Turbulence, advection, and air-sea interaction—on oceanic primary production. In The Sea: Biological-Physical Interactions in the Ocean, ed. by A. R. Robinson, J. J. McCarthy and B. J. Rothschild, John Wiley & Sons (in press).
Garrett, C. (2001): Stirring and mixing: What are the rate-controlling processes? p. 1–8. In Proceedings of the Twelfth ‘Aha Huliko’ a Hawaiian Winter Workshop, ed. by P. Muller and D. Henderson, SOEST.
Garrett, C. and D. Gilbert (1988): Estimates of vertical mixing by internal waves reflected off sloping topography. p. 405–424. In Small-Scale Turbulence and Mixing in the Ocean, ed. by J. C. J. Nihoul and B. M. Janard, Elsevier Scientific.
Garrett, C., P. MacCready and P. Rhines (1993): Boundary mixing and arrested Ekman layers: Rotating stratified flow near a sloping boundary. Ann. Rev. Fluid Mech., 25, 291–323.
Gerkema, T. (2001): Internal and interfacial tides: Beam scattering and local generation of solitary waves. J. Mar. Res., 59, 227–255.
Gnanadesikan, A. (1999): A simple predictive model for the structure of the oceanic pycnocline. Science, 283, 2077–2079.
Gregg, M. C. (1989): Scaling turbulent dissipation in the thermocline. J. Geophys. Res., 94, 9686–9698.
Hendershott, M. C. (1981): Long waves and ocean tides. p. 292–341. In Evolution of Physical Oceanography, ed. by B. A. Warren and C. Wunsch, The MIT Press.
Henyey, F. S., J. Wright and S. M. Flatte (1986): Energy and action flow through the internal wave field: an eikonal approach. J. Geophys. Res., 91, 8487–8495.
Hibiya, T. (1986): Generation mechanism of internal waves by tidal flow over a sill. J. Geophys. Res., 91, 7697–7708.
Hibiya, T. and M. Watanabe (2001): Global estimates of the wind-induced inertial energy. Geophys. Res. Lett. (submitted).
Hirst, E. (1991): Internal wave-wave resonance theory: Fundamentals and limitations. p. 211–226. In Dynamics of Oceanic Internal Gravity Waves, Proc. ‘Aha Huliko’ a Hawaiian Winter Workshop, ed. by P. Muller and D. Henderson, SOEST.
Hogg, N. G., P. Biscaye, E. Gardner and W. J. Schmitz (1982): On the transport of Antarctic Bottom Water in the Vema Channel. J. Mar. Res., 40,Suppl., 231–263.
Holloway, P. E. and M. A. Merrifield (1999): Internal tide generation by seamounts, ridges and islands. J. Geophys. Res., 104, 25,937–25,951.
Huang, R. X. and R. L. Chou (1994): Parameter sensitivity study of the saline circulation. Clim. Dyn., 9, 391–409.
Khatiwala, S. (2001): Generation of internal tides in the ocean. Deep-Sea Res. (submitted).
Kunze, E. and J. M. Toole (1997): Tidally driven vorticity, diurnal shear, and turbulence atop Fieberling Seamount. J. Phys. Oceanogr., 27, 2663–2693.
Kunze, E., L. K. Rosenfeld, G. S. Carter and M. C. Gregg (2001): Internal waves in Monterey Submarine Canyon. J. Phys. Oceanogr. (submitted).
Ledwell, J. R., A. J. Watson and C. S. Law (1998): Mixing of a tracer in the pycnocline. J. Geophys. Res., 103, 21,499–21,529.
Ledwell, J. R., E. T. Montgomery, K. L. Polzin, L. C. St. Laurent, R. W. Schmitt and J. M. Toole (2000): Mixing over rough topography in the Brazil Basin. Nature, 403, 179–182.
Li, M. (2001): Energetics of internal tides radiated from deep-ocean topographic features. J. Phys. Oceanogr. (submitted).
Lien, R.-C. and M. C. Gregg (2001): Observations of turbulence in a tidal beam and across a coastal ridge. J. Geophys. Res., 106, 4575–4592.
Llewellyn Smith, S. G. and W. R. Young (2001): Conversion of the barotropic tide. J. Phys. Oceanogr. (submitted).
Lott, F. and H. Teitelbaum (1993): Linear unsteady mountain waves. Tellus, 45, 201–220.
Lueck, R. G. and T. D. Mudge (1997): Topographically induced mixing around a shallow seamount. Science, 276, 1831–1833.
McComas, C. H. and P. Müller (1981a): The dynamic balance of internal waves. J. Phys. Oceanogr., 11, 970–986.
McComas, C. H. and P. Müller (1981b): Time scales of resonant interactions among oceanic internal waves. J. Geophys. Res., 83, 1397–1412.
McDougall, T. (1991): Parameterizing mixing in inverse models. p. 355–386. In Dynamics of Oceanic Internal Gravity Waves, Proc. ‘Aha Huliko’ a Hawaiian Winter Workshop, ed. by P. Muller and D. Henderson, SOEST.
Merrifield, M. A., P. E. Holloway and T. M. Shaun Johnston (2001): The generation of internal tides at the Hawaiian Ridge. Geophys. Res. Lett., 28, 559–562.
Mihaly, S. F., R. E. Thomson and A. B. Rabinovich (1998): Evidence for nonlinear interaction between internal waves of inertial and semidiurnal frequency. Geophys. Res. Lett., 25, 1205–1208.
Morris, M. Y., M. M. Hall, L. C. St. Laurent and N. G. Hogg (2001): Abyssal mixing in the Brazil Basin. J. Phys. Oceanogr., 31, 3331–3348.
Müller, P. and N. Xu (1992): Scattering of oceanic internal waves off random bottom topography. J. Phys. Oceanogr., 22, 474–488.
Müller, P., G. Holloway, F. Henyey and N. Pomphrey (1986): Nonlinear interactions among internal gravity waves. Rev. Geophys., 24, 493–536.
Munk, W. H. (1966): Abyssal recipes. Deep-Sea Res., 13, 707–730.
Munk, W. and C. Wunsch (1998): Abyssal recipes II: energetics of tidal and wind mixing. Deep-Sea Res., 45, 1977–2010.
Nagasawa, M., Y. Niwa and T. Hibiya (2000): Spatial and temporal distribution of the wind-induced internal wave energy available for deep water mixing in the North Pacific. J. Geophys. Res., 105, 13933–13943.
Nakamura, T., T. Awaji, T. Hatayama and K. Akitomo (2000): The generation of large amplitude unsteady lee waves by subinertial Kl tidal flow: A possible vertical mixing mechanism in the Kuril Straits. J. Phys. Oceanogr., 30, 1601–1621.
New, A. L. and J. C. B. Da Silva (2001): Remote-sensing evidence for the local generation of internal soliton packets in the central Bay of Biscay. Deep-Sea Res. I (in press).
Niwa, Y. and T. Hibiya (2001): Numerical study of the spatial distribution of the M2 internal tide in the Pacific ocean. J. Geophys. Res. (in press).
Olbers, D. J. (1983): Models of the oceanic internal wave field. Rev. Geophys., 21, 1567–1606.
Olbers, D. J. and N. Pomphrey (1981): Disqualifying two candidates for the energy balance of oceanic internal waves. J. Phys. Oceanogr., 11, 1423–1425.
Polzin, K. and E. Firing (1997): Estimates of diapycnal mixing using LADCP and CTD data from I8S. International WOCE Newsletter, 29, 39–42.
Polzin, K. L., J. M. Toole and R. W. Schmitt (1995): Finescale parameterizations of turbulent dissipation. J. Phys. Oceanogr., 25, 306–328.
Polzin, K. L., J. M. Toole, J. R. Ledwell and R. W. Schmitt (1997): Spatial variability of turbulent mixing in the abyssal ocean. Science, 276, 93–96.
Rattray, M., Jr. (1960): On the coastal generation of internal tides. Tellus, 22, 54–62.
Ray, R. and G. T. Mitchum (1996): Surface manifestation of internal tides generated near Hawaii. Geophys. Res. Lett., 23, 2101–2104.
Ray, R. and G. T. Mitchum (1997): Surface manifestation of internal tides in the deep ocean: observations from altimetry and island gauges. Prog. Oceanogr., 40, 135–162.
Robinson, A. R. (ed.) (1983): Eddies in Marine Science. Springer-Verlag, 609 pp.
St. Laurent, L. C. and C. Garrett (2001): The role of internal tides in mixing the deep ocean. J. Phys. Oceanogr. (submitted).
St. Laurent, L. and R. W. Schmitt (1999): The contribution of salt fingers to vertical mixing in the North Atlantic Tracer Release Experiment. J. Phys. Oceanogr., 24, 1404–1424.
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, 3476–3495.
Schmitt, R. W. (1994): Double diffusion in oceanography. Ann. Rev. Fluid Mech., 26, 255–285.
Seibold, E. and W. H. Berger (1996): The Sea Floor—An Introduction to Marine Geology. Springer-Verlag, 356 pp.
Sjöberg, B. and A. Stigebrandt (1992): Computations of the geographical distribution of the energy flux to mixing processes via internal tides and the associated vertical circulation in the ocean. Deep-Sea Res., 39, 269–291.
Sloyan, B. M. and S. R. Rintoul (2001): Circulation, renewal and modification of Antarctic mode and intermediate water. J. Phys. Oceanogr., 31, 1005–1030.
Speer, K., S. R. Rintoul and B. Sloyan (2000): The diabatic Deacon Cell. J. Phys. Oceanogr., 30, 3212–3222.
Stigebrandt, A. (1980): Some aspects of tidal interaction with fjord constriction. Estuar. Coast. Mar. Sci., 11, 151–166.
Sun, H. and E. Kunze (1999a): Internal wave-wave interactions. Part 1: The role of internal wave vertical divergence. J. Phys. Oceanogr., 29, 2886–2904.
Sun, H. and E. Kunze (1999b): Internal wave-wave interactions. Part II: Spectral energy transfer and turbulence production. J. Phys. Oceanogr., 29, 2905–2919.
Tandon, A. and K. Zahariev (2001): Quantifying the role of mixed layer entrainment for water mass transformation in the North Atlantic. J. Phys. Oceanogr., 31, 1120–1131.
Thorpe, S. A. (1998): Nonlinear reflection of internal waves at a density discontinuity at the base of the mixed layer. J. Phys. Oceanogr., 28, 1853–1860.
Toggweiler, J. R. and B. Samuels (1998): On the ocean's large scale circulation near the limit of no vertical mixing. J. Phys. Oceanogr., 28, 1832–1852.
Toole, J. M., J. R. Ledwell, K. L. Polzin, R. W. Schmitt, E. T. Montgomery, L. St. Laurent and W. B. Owens (1997): The Brazil Basin Tracer Release Experiment. International WOCE Newsletter, 28, 25–28.
Webb, D. J. and N. Suginohara (2001): Vertical mixing in the ocean. Nature, 409, 37.
Wunsch, C. (1975): Internal tides in the ocean. Rev. Geophys., 13, 167–182.
Wunsch, C. (1996): The Ocean Circulation Inverse Problem. Cambridge University Press, 442 pp.
Wunsch, C. (1998): The work done by the wind on the ocean circulation. J. Phys. Oceanogr., 28, 2331–2339.
Wunsch, C. and D. Stammer (1998): Satellite altimetry, the marine geoid and the oceanic general circulation. Annu. Rev. Earth Planet. Sci., 26, 219–253.
Yamazaki, H., D. L. Mackas and K. L. Denman (2001): Coupling small scale physical processes with biology. In The Sea: Biological-Physical Interactions in the Ocean, ed. by A. R. Robinson, J. J. McCarthy and B. J. Rothschild, John Wiley & Sons (in press).
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Garrett, C., St. Laurent, L. Aspects of Deep Ocean Mixing. Journal of Oceanography 58, 11–24 (2002). https://doi.org/10.1023/A:1015816515476
Issue Date:
DOI: https://doi.org/10.1023/A:1015816515476