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Title: Down-Scaling Model Resolution to Illuminate the Internal Wave Field in a Small Stratified Lake Authored by: Botelho, D. and Imberger, J. Abstract:
This paper presents the application of hydrostatic and non-hydrostatic three-dimensional hydrodynamic model simulations to a small stratified lake. Focus was given in the multi-scale response of the internal wave field to a strong wind pulse with gusts exceeding 20 m s-1. Simulations were carried on different horizontal resolutions with uniform grid sizes varying from 100x100m to 10x10m. Results from a 20x20 m horizontal grid size using a hydrostatic model were used as initial conditions for the non-hydrostatic simulations on the smaller grids. Wavelength of the high frequency waves varied with grid resolution however; none of the grids were sufficiently fine to capture the waves of the highest frequency. Simulation carried out in a non-uniform grid produced internal waves of similar frequency and for the same duration of the waves observed in the field. The simulations showed that these waves were part of shear instabilities modes. Vertical and horizontal length scales of the most unstable modes were in close agreement with results from linear stability analysis.
Reference: Botelho, D. and Imberger, J., 2007, Down-Scaling Model Resolution to Illuminate the Internal Wave Field in a Small Stratified Lake, 133:1206-1218 Keywords: ELCOM |
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