• Danioux, E., and P. Klein, 2008: A resonance mechanism leading to wind-forced motions with a 2f frequency. J. Phys. Oceanogr., 38, 23222329.

    • Search Google Scholar
    • Export Citation
  • Danioux, E., P. Klein, and P. Rivière, 2008: Propagation of wind energy into the deep ocean through a fully turbulent eddy field. J. Phys. Oceanogr., 38, 22242241.

    • Search Google Scholar
    • Export Citation
  • D’Asaro, E. A., 1995: Upper-ocean inertial currents forced by a strong storm. Part III: Interaction of inertial currents and mesoscale eddies. J. Phys. Oceanogr., 25, 29532958.

    • Search Google Scholar
    • Export Citation
  • D’Asaro, E. A., and R. Lien, 2000: The wave–turbulence transition for stratified flows. J. Phys. Oceanogr., 30, 16691678.

  • Ferrari, R., and C. Wunsch, 2009: Ocean circulation kinetic energy: Reservoirs, sources and sinks. Annu. Rev. Fluid Mech., 41, 253282.

    • Search Google Scholar
    • Export Citation
  • Flierl, G. R., 1978: Models of vertical structure and the calibration of two-layer models. Dyn. Atmos. Oceans, 2, 341381.

  • Furuichi, N., T. Hibiya, and Y. Niwa, 2008: Model-predicted distribution of wind-induced internal wave energy in the world’s oceans. J. Geophys. Res., 113, C09034, doi:10.1029/2008JC004768.

    • Search Google Scholar
    • Export Citation
  • Gill, A. E., 1982: Atmosphere–Ocean Dynamics. Academic Press, 662 pp.

  • Gill, A. E., 1984: On the behavior of internal waves in the wakes of storms. J. Phys. Oceanogr., 14, 11291151.

  • Hecht, M., and H. Hasumi, 2008: Ocean Modeling in an Eddying Regime. Geophys. Monogr., Vol. 177, Amer. Geophys. Union, 500 pp.

  • Hibiya, T., Y. Niwa, and K. Fujiwara, 1998: Numerical experiments of nonlinear energy transfer within the oceanic internal wave spectrum. J. Geophys. Res., 103, 18 71518 722.

    • Search Google Scholar
    • Export Citation
  • Klein, P., G. Lapeyre, and W. G. Large, 2004a: Wind ringing of the ocean in presence of mesoscale eddies. Geophys. Res. Lett., 31, L15306, doi:10.1029/2004GL020274.

    • Search Google Scholar
    • Export Citation
  • Klein, P., S. Llewellyn-Smith, and G. Lapeyre, 2004b: Spatial organisation of inertial energy by an eddy field. Quart. J. Roy. Meteor. Soc., 130, 11531166.

    • Search Google Scholar
    • Export Citation
  • Klein, P., B. Hua, G. Lapeyre, X. Capet, S. L. Gentil, and H. Sasaki, 2008: Upper ocean turbulence from high-resolution 3D simulations. J. Phys. Oceanogr., 38, 17481763.

    • Search Google Scholar
    • Export Citation
  • Komori, N., W. Ohfuchi, B. Taguchi, H. Sasaki, and P. Klein, 2008: Deep ocean inertia-gravity waves simulated in a high-resolution global coupled atmosphere–ocean GCM. Geophys. Res. Lett., 35, L04610, doi:10.1029/2007GL032807.

    • Search Google Scholar
    • Export Citation
  • Kunze, E., 1985: Near-inertial wave propagation in geostrophic shear. J. Phys. Oceanogr., 15, 544565.

  • Large, W. G., S. C. Doney, and J. C. McWilliams, 1994: Oceanic vertical mixing: A review and a model with a non-local k-profile boundary layer parameterization. Rev. Geophys., 32, 363403.

    • Search Google Scholar
    • Export Citation
  • Lévy, M., P. Klein, and A.-M. Tréguier, 2001: Impact of sub-mesoscale physics on production and subduction of phytoplankton in an oligotrophic regime. J. Mar. Res., 59, 535565.

    • Search Google Scholar
    • Export Citation
  • MacKinnon, J. A., and K. B. Winters, 2005: Subtropical catastrophe: Significant loss of low-mode tidal energy at 28.9°. Geophys. Res. Lett., 32, L15605, doi:10.1029/2005GL023376.

    • Search Google Scholar
    • Export Citation
  • Rivière, P., A.-M. Tréguier, and P. Klein, 2004: Effects of bottom friction on nonlinear equilibration of an oceanic baroclinic jet. J. Phys. Oceanogr., 34, 416432.

    • Search Google Scholar
    • Export Citation
  • Shchepetkin, A. F., and J. C. McWilliams, 2009: Computational kernel algorithms for fine-scale, multiprocess, longtime oceanic simulations. Special Volume: Computational Methods for the Atmosphere and the Oceans, R. Teman and J. Tribbia, Eds., Vol. 14, Handbook of Numerical Analysis, Elsevier, 121–186.

    • Search Google Scholar
    • Export Citation
  • Staquet, C., and J. Sommeria, 2002: Internal gravity waves: From instabilities to turbulence. Annu. Rev. Fluid Mech., 34, 559593.

  • Young, W. R., and M. Ben Jelloul, 1997: Propagation of near-inertial oscillations through a geostrophic flow. J. Mar. Res., 55, 735766.

    • Search Google Scholar
    • Export Citation
  • Zhai, X., R. J. Greatbach, and J. Zhao, 2005: Enhanced vertical propagation of storm-induced near-inertial energy in an eddying ocean channel model. Geophys. Res. Lett., 32, L18602, doi:10.1029/2005GL023643.

    • Search Google Scholar
    • Export Citation
  • Zhai, X., R. Greatbach, C. Eden, and T. Hibiya, 2009: On the loss of wind-induced near-inertial energy to turbulent mixing in the upper ocean. J. Phys. Oceanogr., 39, 30403045.

    • Search Google Scholar
    • Export Citation
All Time Past Year Past 30 Days
Abstract Views 0 0 0
Full Text Views 4 4 4
PDF Downloads 4 4 4

Emergence of Wind-Driven Near-Inertial Waves in the Deep Ocean Triggered by Small-Scale Eddy Vorticity Structures

View More View Less
  • 1 Laboratoire de Physique des Océans, IFREMER/CNRS/UBO/IRD, Plouzané, France
  • | 2 Los Alamos National Laboratory, Los Alamos, New Mexico
  • | 3 Earth Simulator Center, JAMSTEC, Yokohama, Japan
  • | 4 Laboratoire de Physique des Océans, IFREMER/CNRS/UBO/IRD, Plouzané, France
Restricted access

Abstract

Using numerical simulations forced by a uniform realistic wind time series, the authors show that the presence of a mesoscale eddy field at midlatitudes accelerates the vertical propagation of the wind-forced near-inertial waves (NIW) and produces the emergence of a maximum of vertical velocity into the deep ocean (around 2500 m) characterized by a mean amplitude of 25 m day−1, a dominant 2f frequency, and scales as small as O(30 km). These results differ from previous studies that reported a smaller depth and larger scales. The authors show that the larger depth observed in the present study (2500 m instead of 1700 m) is due to the wind forcing duration that allows the first five baroclinic modes to disperse and to impact the deep NIW maximum (instead of the first two modes as reported before). The smaller scales (30 km instead of 90 km) are explained by a resonance mechanism (described in previous studies) that affects the high NIW baroclinic modes, but only when small-scale relative vorticity structures (related to the mesoscale eddy field) have an amplitude that is large enough. These results, which point out the importance of the wind forcing duration and the resolution, indicate that the emergence of a deep NIW maximum with a 2f frequency reported before is a robust feature that is enhanced with more realistic conditions. Such 2f frequency in the deep interior raises the question of the mechanisms, still unresolved, that may ultimately transfer this superinertial energy into mixing at these depths.

Corresponding author address: P. Klein, LPO, IFREMER, BP 70, 29280 Plouzané, France. E-mail: patrice.klein@ifremer.fr

Abstract

Using numerical simulations forced by a uniform realistic wind time series, the authors show that the presence of a mesoscale eddy field at midlatitudes accelerates the vertical propagation of the wind-forced near-inertial waves (NIW) and produces the emergence of a maximum of vertical velocity into the deep ocean (around 2500 m) characterized by a mean amplitude of 25 m day−1, a dominant 2f frequency, and scales as small as O(30 km). These results differ from previous studies that reported a smaller depth and larger scales. The authors show that the larger depth observed in the present study (2500 m instead of 1700 m) is due to the wind forcing duration that allows the first five baroclinic modes to disperse and to impact the deep NIW maximum (instead of the first two modes as reported before). The smaller scales (30 km instead of 90 km) are explained by a resonance mechanism (described in previous studies) that affects the high NIW baroclinic modes, but only when small-scale relative vorticity structures (related to the mesoscale eddy field) have an amplitude that is large enough. These results, which point out the importance of the wind forcing duration and the resolution, indicate that the emergence of a deep NIW maximum with a 2f frequency reported before is a robust feature that is enhanced with more realistic conditions. Such 2f frequency in the deep interior raises the question of the mechanisms, still unresolved, that may ultimately transfer this superinertial energy into mixing at these depths.

Corresponding author address: P. Klein, LPO, IFREMER, BP 70, 29280 Plouzané, France. E-mail: patrice.klein@ifremer.fr
Save