Redistribution of energy available for ocean mixing by long-range propagation of internal waves

Ocean mixing, which affects pollutant dispersal, marine productivity and global climate, largely results from the breaking of internal gravity waves—disturbances propagating along the ocean's internal stratification. A global map of internal-wave dissipation would be useful in improving climate models, but would require knowledge of the sources of internal gravity waves and their propagation. Towards this goal, I present here computations of horizontal internal-wave propagation from 60 historical moorings and relate them to the source terms of internal waves as computed previously. Analysis of the two most energetic frequency ranges—near-inertial frequencies and semidiurnal tidal frequencies—reveals that the fluxes in both frequency bands are of the order of 1 kW m-1 (that is, 15–50% of the energy input) and are directed away from their respective source regions. However, the energy flux due to near-inertial waves is stronger in winter, whereas the tidal fluxes are uniform throughout the year. Both varieties of internal waves can thus significantly affect the space-time distribution of energy available for global mixing.

[1]  K. Kornev,et al.  Classification of Equilibrium Configurations of Wetting Films on Planar Substrates , 2000 .

[2]  Daniel E. Frye,et al.  A MOORED PROFILING INSTRUMENT , 1999 .

[3]  Syukuro Manabe,et al.  Two Stable Equilibria of a Coupled Ocean-Atmosphere Model , 1988 .

[4]  A. E. Gill.  On the Behavior of Internal Waves in the Wakes of Storms , 1984 .

[5]  M. Alford,et al.  Near‐inertial mixing: Modulation of shear, strain and microstructure at low latitude , 2001 .

[6]  C. A. Murray,et al.  Layering in colloidal fluids near a smooth repulsive wall , 1988 .

[7]  Nikolov,et al.  Structure of charged colloids under a wedge confinement , 2000, Physical review. E, Statistical physics, plasmas, fluids, and related interdisciplinary topics.

[8]  E. D’Asaro.  Upper Ocean Temperature Structure, Inertial Currents, and Richardson Numbers Observed during Strong Meteorological Forcing , 1985 .

[9]  P. Holloway,et al.  Model estimates of M2 internal tide energetics at the Hawaiian Ridge , 2002 .

[10]  Lee-Lueng Fu,et al.  Observations and Models of Inertial Waves in the Deep Ocean (Paper 80R1297) , 1981 .

[11]  N. Churaev.  On the forces of hydrophobic attraction in wetting films of aqueous solutions , 1993 .

[12]  W. Munk,et al.  Abyssal recipes II: energetics of tidal and wind mixing , 1998 .

[13]  M. Alford.  Internal Swell Generation: The Spatial Distribution of Energy Flux from the Wind to Mixed Layer Near-Inertial Motions , 2001 .

[14]  S. Herminghaus,et al.  Wetting: Statics and dynamics , 1997 .

[15]  L. S. Laurent,et al.  The Role of Internal Tides in Mixing the Deep Ocean , 2002 .

[16]  J. M. Toole,et al.  Spatial Variability of Turbulent Mixing in the Abyssal Ocean , 1997, Science.

[17]  C. Paulson,et al.  Upper-Ocean Inertial Currents Forced by a Strong Storm. Part I: Data and Comparisons with Linear Theory , 1995 .

[18]  Gary T. Mitchum,et al.  Surface manifestation of internal tides in the deep ocean: observations from altimetry and island gauges , 1997 .

[19]  V. Starov,et al.  The Superspreading Effect of Trisiloxane Surfactant Solutions , 2001 .

[20]  A. Nikolov,et al.  Contact angles of thin liquid films: Interferometric determination , 1990 .

[21]  Carl Wunsch,et al.  The Work Done by the Wind on the Oceanic General Circulation , 1998 .

[22]  D. Cartwright,et al.  Estimates of internal tide energy fluxes from Topex/Poseidon Altimetry: Central North Pacific , 2001 .

[23]  A. Nikolov,et al.  Accuracy of the Differential-interferometric Measurements of Curvature , 1986 .

[24]  M. Gregg,et al.  Diapycnal mixing in the thermocline: A review , 1987 .

[25]  E. Ruckenstein.  Effect of Short-Range Interactions on Spreading , 1996 .

[26]  E. D’Asaro.  The Energy Flux from the Wind to Near-Inertial Motions in the Surface Mixed Layer , 1985 .

[27]  Rachid Chebbi.  Dynamics of Wetting. , 2000, Journal of colloid and interface science.

[28]  Chris Garrett,et al.  Space-Time Scales of Internal Waves' A Progress Report , 1975 .

[29]  Carl Wunsch,et al.  Improved estimates of global ocean circulation, heat transport and mixing from hydrographic data , 2000, Nature.

[30]  P. Pieranski,et al.  Thin Colloidal Crystals , 1983 .

[31]  Andrew J. Watson,et al.  Evidence for slow mixing across the pycnocline from an open-ocean tracer-release experiment , 1993, Nature.

[32]  M. Alford,et al.  Improved global maps and 54‐year history of wind‐work on ocean inertial motions , 2003 .

[33]  A. Nikolov,et al.  Structure and Pressure of a Hard Sphere Fluid in a Wedge-Shaped Cell or Meniscus , 1999 .

[34]  A. Nikolov,et al.  Mechanisms of Oil Removal from a Solid Surface in the Presence of Anionic Micellar Solutions , 1988 .

[35]  Rob A. Hall,et al.  Internal Tides in Monterey Submarine Canyon , 2002 .

[36]  Bruce M. Howe,et al.  Barotropic and Baroclinic Tides in the Central North Pacific Ocean Determined from Long-Range Reciprocal Acoustic Transmissions , 1995 .

[37]  G. D. Egbert,et al.  Significant dissipation of tidal energy in the deep ocean inferred from satellite altimeter data , 2000, Nature.

[38]  L. Yang,et al.  Numerical simulations of a storm‐generated island‐trapped wave event at the Hawaiian Islands , 2002 .

[39]  S. Thorpe.  On Internal Wave Groups , 1999 .

[40]  A. Nikolov,et al.  Contact angle of air bubbles attached to an air-water surface in foam applications , 1990 .

[41]  A. New,et al.  Abyssal penetration and bottom reflection of internal tidal energy in the bay of Biscay , 1991 .

[42]  Steven S. Lapham,et al.  Thin Films , 1996, Science.

[43]  S. Gorshkov,et al.  World ocean atlas , 1976 .

[44]  C. Garrett.  What is the near-inertial band and why is it different from the rest of the internal wave spectrum? , 2001 .

[45]  R. Samelson.  Large-Scale Circulation with Locally Enhanced Vertical Mixing* , 1998 .

[46]  Douglas Henderson,et al.  A Simple Calculation of Structural and Depletion Forces for Fluids/Suspensions Confined in a Film , 2001 .

[47]  W. Rossiter,et al.  Progress report , 1954, Research newsletter. College of General Practitioners.