Author(s): Marco Toffolon
Linked Author(s):
Keywords: Wind-induced circulation; Wind inhomogeneity; Turbulence anisotropy; Stratification; Closed basin
Abstract: A simple model is proposed to understand the role of geometrical features and turbulence anisotropy in determining the barotropic response of a closed basin to inhomogeneities of wind forcing. The development of planimetric (depth-averaged) circulations superimposed to circulations in the vertical plane is studied in the central part of a schematic rectangular basin, within the framework of an analytical three-dimensional model. Taking advantage of some simplifying assumptions, an explicit relationship for the velocity field is obtained as a function of the ratio between the vertical and the horizontal eddy viscosity and of the ratio between the transversal length and the depth of the basin. A single parameter governing the phenomenon is identified, which can be used to predict the response of a lake to lateral variations of the wind stress acting on the surface. Moreover, the estimation of the intensity of planimetric circulations may give some clues about the possibility to use depth-averaged models in numerical simulations of lake hydrodynamics.
Year: 2007