Modeling basin-scale internal waves in a stratified lake

摘要: Basin-scale internal waves provide the driving forces for vertical and horizontal fluxes in a stratified lake below wind-mixed layer. Thus, correct modeling of mixing transport requires accurate basin- scale waves: examining this capability with hydrostatic, z-coordinate three-dimensional (3D) numerical model at coarse grid resolutions is focus paper. It demonstrated that capturing thermocline forcing 3D mixed-layer surface dynamics results good representation low-frequency wave dynamics. The estuary computer ELCOM applied to Lake Kinneret, Israel, compared field data under summer stratification conditions identify illustrate spatial structure lowest-mode basin-scale Kelvin Poincarewaves largest two peaks energy spectra. solves unsteady Reynolds-averaged Navier-Stokes equations using semi-implicit method similar momentum solution TRIM code addition quadratic Euler-Lagrange dis- cretization, scalar (e.g., temperature) conservative flux-limited approach, elimination diffusion terms governing equations. A detailed description provided turbulence closure Reynolds stress turbulent parameterized on wind shear instead convential eddy viscosity/diffusivity assumption. This approach gives depth allows be energized correctly basin scale. Wind stresses, heating, density currents form lake. flux from particular interest because its dominant role setting motion, which, absence inflows outflows, primary store behavior an priori requirement quantifying paths nutrients (Imberger 1994). paper takes first step direction by analyzing our ability are seen Israel. Energy path —Energy through has fundamental dependence forced free baroclinic motions. imparts both kinetic (TKE) water sur- face TKE distributes vertically