Low-Mode Internal Tide Propagation in a Turbulent Eddy Field

Michael Dunphy University of Brest, CNRS, IRD, Ifremer, Laboratoire d’Océanographie Physique et Spatiale, IUEM, Brest, France

Search for other papers by Michael Dunphy in
Current site
Google Scholar
PubMed
Close
,
Aurélien L. Ponte University of Brest, CNRS, IRD, Ifremer, Laboratoire d’Océanographie Physique et Spatiale, IUEM, Brest, France

Search for other papers by Aurélien L. Ponte in
Current site
Google Scholar
PubMed
Close
,
Patrice Klein University of Brest, CNRS, IRD, Ifremer, Laboratoire d’Océanographie Physique et Spatiale, IUEM, Brest, France

Search for other papers by Patrice Klein in
Current site
Google Scholar
PubMed
Close
, and
Sylvie Le Gentil University of Brest, CNRS, IRD, Ifremer, Laboratoire d’Océanographie Physique et Spatiale, IUEM, Brest, France

Search for other papers by Sylvie Le Gentil in
Current site
Google Scholar
PubMed
Close
Restricted access

Abstract

Understanding and predicting how internal tides distort and lose coherence as they propagate through the ocean has been identified as a key issue for interpreting data from the upcoming wide-swath altimeter mission Surface Water and Ocean Topography (SWOT). This study addresses the issue through the analysis of numerical experiments where a low-mode internal tide propagates through a quasigeostrophic turbulent jet. Equations of motion linearized around the slower turbulent field are projected onto vertical modes and assumed to describe the dynamics of the low-mode internal tide propagation. Diagnostics of the terms responsible for the interaction between the wave and the slow circulation are computed from the numerical outputs. The large-scale change of stratification, on top of eddies and jet meanders, contributes significantly to these interaction terms, which is shown to be consistent with an independent scaling analysis. The sensitivity of interaction terms to a degradation of the slow field spatial and temporal resolution indicates that present-day observing systems (Argo network, altimetry) may lack the spatial resolution necessary to correctly predict internal tide evolution. The upcoming SWOT satellite mission may improve upon this situation. The number of vertical modes required to properly estimate interaction terms is discussed. These results advocate development of a simplified model based on solving a modest number of the linearized equations subject to a prescribed mesoscale field and internal tide sources.

Current affiliation: California Institute of Technology, and Jet Propulsion Laboratory, NASA, Pasadena, California.

© 2017 American Meteorological Society. For information regarding reuse of this content and general copyright information, consult the AMS Copyright Policy (www.ametsoc.org/PUBSReuseLicenses).

Corresponding author e-mail: Michael Dunphy, mdunphy@uwaterloo.ca

Abstract

Understanding and predicting how internal tides distort and lose coherence as they propagate through the ocean has been identified as a key issue for interpreting data from the upcoming wide-swath altimeter mission Surface Water and Ocean Topography (SWOT). This study addresses the issue through the analysis of numerical experiments where a low-mode internal tide propagates through a quasigeostrophic turbulent jet. Equations of motion linearized around the slower turbulent field are projected onto vertical modes and assumed to describe the dynamics of the low-mode internal tide propagation. Diagnostics of the terms responsible for the interaction between the wave and the slow circulation are computed from the numerical outputs. The large-scale change of stratification, on top of eddies and jet meanders, contributes significantly to these interaction terms, which is shown to be consistent with an independent scaling analysis. The sensitivity of interaction terms to a degradation of the slow field spatial and temporal resolution indicates that present-day observing systems (Argo network, altimetry) may lack the spatial resolution necessary to correctly predict internal tide evolution. The upcoming SWOT satellite mission may improve upon this situation. The number of vertical modes required to properly estimate interaction terms is discussed. These results advocate development of a simplified model based on solving a modest number of the linearized equations subject to a prescribed mesoscale field and internal tide sources.

Current affiliation: California Institute of Technology, and Jet Propulsion Laboratory, NASA, Pasadena, California.

© 2017 American Meteorological Society. For information regarding reuse of this content and general copyright information, consult the AMS Copyright Policy (www.ametsoc.org/PUBSReuseLicenses).

Corresponding author e-mail: Michael Dunphy, mdunphy@uwaterloo.ca
Save
  • Arbic, B. K., A. J. Wallcraft, and E. J. Metzger, 2010: Concurrent simulation of the eddying general circulation and tides in a global ocean model. Ocean Modell., 32, 175187, doi:10.1016/j.ocemod.2010.01.007.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Arbic, B. K., F. Lyard, A. Ponte, R. Ray, J. G. Richman, J. F. Shriver, E. Zaron, and Z. Zhao, 2015: Tides and the SWOT mission: Transition from science definition team to science team. Tech. Rep. CNES-NASA, 8 pp.

  • Bühler, O., 2014: Waves and Mean Flows. 2nd ed. Cambridge University Press, 360 pp.

  • Bühler, O., and M. E. McIntyre, 2005: Wave capture and wave-vortex duality. J. Fluid Mech., 534, 6795, doi:10.1017/S0022112005004374.

  • Danioux, E., J. Vanneste, and O. Bühler, 2015: On the concentration of near-inertial waves in anticyclones. J. Fluid Mech., 773, R2, doi:10.1017/jfm.2015.252.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Dufau, C., M. Orsztynowicz, G. Dibarboure, R. Morrow, and P.-Y. Le Traon, 2016: Mesoscale resolution capability of altimetry: Present and future. J. Geophys. Res. Oceans, 121, 49104927, doi:10.1002/2015JC010904.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Dunphy, M., and K. G. Lamb, 2014: Focusing and vertical mode scattering of the first mode internal tide by mesoscale eddy interaction. J. Geophys. Res. Oceans, 119, 523536, doi:10.1002/2013JC009293.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Ferrari, R., and C. Wunsch, 2010: The distribution of eddy kinetic and potential energies in the global ocean. Tellus, 62A, 92108, doi:10.3402/tellusa.v62i2.15680.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Fu, L.-L., and G. R. Flierl, 1980: Nonlinear energy and enstrophy transfers in a realistically stratified ocean. Dyn. Atmos. Oceans, 4, 219246, doi:10.1016/0377-0265(80)90029-9.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Garrett, C., and E. Kunze, 2007: Internal tide generation in the deep ocean. Annu. Rev. Fluid Mech., 39, 5787, doi:10.1146/annurev.fluid.39.050905.110227.

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

  • Griffiths, S. D., and R. H. Grimshaw, 2007: Internal tide generation at the continental shelf modeled using a modal decomposition: Two-dimensional results. J. Phys. Oceanogr., 37, 428451, doi:10.1175/JPO3068.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Kelly, S. M., N. L. Jones, and J. D. Nash, 2013: A coupled model for Laplace’s tidal equations in a fluid with one horizontal dimension and variable depth. J. Phys. Oceanogr., 43, 17801797, doi:10.1175/JPO-D-12-0147.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Kerry, C. G., B. S. Powell, and G. S. Carter, 2014: The impact of subtidal circulation on internal-tide-induced mixing in the Philippine Sea. J. Phys. Oceanogr., 44, 32093224, doi:10.1175/JPO-D-13-0249.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Klein, P., B. L. Hua, G. Lapeyre, X. Capet, S. L. Gentil, and H. Sasaki, 2008: Upper ocean turbulence from high-resolution 3D simulations. J. Phys. Oceanogr., 38, 17481762, doi:10.1175/2007JPO3773.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Klein, P., and Coauthors, 2015: Mesoscale/submesoscale dynamics in the upper ocean. Tech. Rep. CNES-NASA, 13 pp.

  • Le Traon, P. Y., 2013: From satellite altimetry to Argo and operational oceanography: Three revolutions in oceanography. Ocean Sci., 9, 901915, doi:10.5194/os-9-901-2013.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Plougonven, R., and C. Snyder, 2005: Gravity waves excited by jets: Propagation versus generation. Geophys. Res. Lett., 32, L18802, doi:10.1029/2005GL023730.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Polzin, K. L., 2010: Mesoscale eddy-internal wave coupling. Part II: Energetics and results from PolyMode. J. Phys. Oceanogr., 40, 789801, doi:10.1175/2009JPO4039.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Rainville, L., and R. Pinkel, 2006: Propagation of low-mode internal waves through the ocean. J. Phys. Oceanogr., 36, 12201236, doi:10.1175/JPO2889.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Ray, R. D., and E. D. Zaron, 2011: Non-stationary internal tides observed with satellite altimetry. Geophys. Res. Lett., 38, L17609, doi:10.1029/2011GL048617.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Richman, J. G., B. K. Arbic, J. F. Shriver, E. J. Metzger, and A. J. Wallcraft, 2012: Inferring dynamics from the wavenumber spectra of an eddying global ocean model with embedded tides. J. Geophys. Res., 117, C12012, doi:10.1029/2012JC008364.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Rocha, C. B., T. Chereskin, S. T. Gille, and D. Menemenlis, 2016: Mesoscale to submesoscale wavenumber spectra in Drake Passage. J. Phys. Oceanogr., 46, 601620, doi:10.1175/JPO-D-15-0087.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Shchepetkin, A. F., and J. C. McWilliams, 2005: The Regional Oceanic Modeling System (ROMS): A split-explicit, free-surface, topography-following-coordinate oceanic model. Ocean Modell., 9, 347404, doi:10.1016/j.ocemod.2004.08.002.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Shriver, J. F., J. G. Richman, and B. K. Arbic, 2014: How stationary are the internal tides in a high-resolution global ocean circulation model? J. Geophys. Res. Oceans, 119, 27692787, doi:10.1002/2013JC009423.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Vallis, G. K., 2006: Atmospheric and Oceanic Fluid Dynamics. Cambridge University Press, 745 pp.

    • Crossref
    • Export Citation
  • Wagner, G. L., 2016: On the coupled evolution of oceanic internal waves and quasi-geostrophic flow. Ph.D. thesis, University of California, San Diego, 216 pp.

  • Wagner, G. L., and W. R. Young, 2016: A three-component model for the coupled evolution of near-inertial waves, quasi-geostrophic flow and the near-inertial second harmonic. J. Fluid Mech., 802, 806837, doi:10.1017/jfm.2016.487.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Ward, M. L., and W. K. Dewar, 2010: Scattering of gravity waves by potential vorticity in a shallow-water fluid. J. Fluid Mech., 663, 478506, doi:10.1017/S0022112010003721.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Xie, J.-H., and J. Vanneste, 2015: A generalised-Lagrangian-mean model of the interactions between near-inertial waves and mean flow. J. Fluid Mech., 774, 143169, doi:10.1017/jfm.2015.251.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Young, W. R., and M. Ben Jelloul, 1997: Propagation of near-inertial oscillations through a geostrophic flow. J. Mar. Res., 55, 735766, doi:10.1357/0022240973224283.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Zaron, E. D., 2015: Non-stationary internal tides observed using dual-satellite altimetry. J. Phys. Oceanogr., 45, 22392246, doi:10.1175/JPO-D-15-0020.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Zaron, E. D., and G. D. Egbert, 2014: Time-variable refraction of the internal tide at the Hawaiian Ridge. J. Phys. Oceanogr., 44, 538557, doi:10.1175/JPO-D-12-0238.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
All Time Past Year Past 30 Days
Abstract Views 0 0 0
Full Text Views 936 202 11
PDF Downloads 584 147 9