TWIST website.

TWIST (Turbulence and Waves over Irregular Sloping Topography)

  • A paper describing this work has been accepted for publication in the Journal of Physical Oceanography: "Internal Tide Reflection and Turbulent Mixing on the Continental Slope", by Jonathan D. Nash, Eric Kunze, John M. Toole, and Ray W. Schmitt.
  • A pdf file of Ocean Sciences 2002 Talk "Shear Intensification through Near-Critical Reflection of Low-Mode Internal Waves" (With E. Kunze, K. Polzin, J. Toole and R. Schmitt) gives an overview of this work in progress.


    • Movies of plane reflection from bathymetry near the TWIST site:

    As part of this analysis, simulations were performed to observe how shear of a low-mode internal wave is intensified upon reflection by the approximate two-dimensional bathymetry at the TWIST site. In these simulations, an upward and downward propagating internal wave at x=0 interacts to form a standing mode in the vertical. This wave propagates onshore and reflects from the continental slope. Topography with a slope similar to that of the propagating rays intensifies velocity and shear. In these simulations, N is constant, and the internal wave characteristics have slope of 0.02. The bathymetry has been WKB-stretched; corrugations in the along-slope direction have been ignored.

    Reflection of low-mode internal waves with 2 cm/s amplitude: CONCLUDE: Internal wave reflection is a likely source of the intense mixing observed at TWIST.

    Movies of plane reflection from idealized supercritical slope:

    For a simplified view of wave reflection, we show in the following simple reflection from a plane surface. From top to bottom, the seven panels show internal waves propagating:


    The narrowest and most intense reflected beams are associated with bottom slopes close to critical (0.02). Simulations were performed with the following bottom slopes:

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