Mechanisms of turbulent mixing in the Continental Shelf bottom boundary layer
Citable URI
https://hdl.handle.net/1912/4107Location
New England shelfDOI
10.1575/1912/4107Abstract
The bottom boundary layer is an important dynamical region of shallow water flows.
In this thesis, the problem of turbulent mixing in the coastal bottom boundary layer is
investigated with a unique set of field measurements of velocity and sound speed that span
a significant fraction of the boundary layer obtained over a six-week long period in the late
summer of 1996 on the New England shelf. The energetics of the turbulent fluctuations are
investigated by testing simplified budgets for turbulent kinetic energy and scalar variance.
The turbulent kinetic energy budget is locally balanced while the scalar variance budget is
not, probably due to turbulent diffusion. The direct effects of stratification are consistently
significant only in the outer part of the boundary layer, where the flux Richardson number
is approximately equal to a critical value of 0.2. Turbulence closure is investigated in terms
of non-dimensional profiles of velocity and sound speed. Close to the bottom, the results are
consistent with Monin-Obukhov similarity theory, while in the outer part of the boundary
layer other scales including the height of the boundary layer are important for setting the
turbulent length scale.
Description
Submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy at the Massachusetts Institute of Technology and the Woods Hole Oceanographic Institution September 1999
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Suggested Citation
Thesis: Shaw, William J., "Mechanisms of turbulent mixing in the Continental Shelf bottom boundary layer", 1999-09, DOI:10.1575/1912/4107, https://hdl.handle.net/1912/4107Related items
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