ISSN:
0271-2091
Schlagwort(e):
internal tides
;
shelf edge
;
stratification
;
turbulence energy
;
baroclinic
;
eddy viscosity
;
Engineering
;
Numerical Methods and Modeling
Quelle:
Wiley InterScience Backfile Collection 1832-2000
Thema:
Maschinenbau
Notizen:
A non-linear, three dimensional, baroclinic model with a range of turbulence energy submodels and algebraic models for the vertical mixing of momentum and density, is used in a cross shelf form to examine the spatial variation of vertical mixing due to the internal tide at the shelf edge off the west coast of Scotland. Particular emphasis is placed on the sensitivity of the mixing to the form of the parameterization of the subgrid scale processes. Calculations using a fine finite difference grid in the horizontal of the order of 0.6 km with 50 sigma levels in the vertical and a typical winter time stratification, show that the model can reproduce the major features of the internal tide with the range of parameterizations considered here, although there are some differences in the magnitude of both the velocity and mixing intensity of the internal tide, depending upon the parameterization of the mixing. In particular, the turbulence energy models show regions of intense mixing at the sea bed where the internal tide is generated and at the sea surface above the shelf break associated with the shear production of turbulence. These differences suggest that detailed measurements of current, internal displacement of density fields and turbulence dissipation rate may be able to assess the accuracy of the various mixing models. Calculations, however, show that the internal tide is particularly sensitive to small perturbations in the initial density field, suggesting that besides detailed measurements to validate the model, a detailed synoptic data set is required for model initialization. © 1998 John Wiley & Sons, Ltd.
Zusätzliches Material:
12 Ill.
Materialart:
Digitale Medien
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