Lake Kinneret is Israel's only fresh water lake (unless you count the Dead Sea). It spans roughly 20km from north to south, and about 12km at its widest east west extent. It is not quite 50m deep at its deepest point. In late spring, the lake stratifies significantly and remains stratified throughout the fall. During the time the lake is stratified, it exhibits low horizontal mode semi-diurnal inertial motions in response to surface forcing from diurnal winds. This internal motion is known to be important in the ecological and chemical balances of the lake, and is suspected to be responsible for episodes in which large numbers of fish are killed. The physical response of the lake to wind forcing is studied. The lake hydrodynamics is approximated by a (x,y,t) two and three layer model on the f-plane (rotating frame) with detailed bathymetry. The numerical method for the integration of the nonlinear partial differential equation is presented, as well as, the generation of the elliptic grid used in the spatial discretization of the Kinneret domain. A suite of numerical simulations are compared to the available data in the northwestern part of the lake. The nonlinear effects, as well as, the sloping beach problem are discussed in the appendixes. / Graduation date: 2000

The Spectral Ocean Wave Model (SOWM) is a numerical wave prediction model which calculates directional wave spectra from input wind fields. As do the majority of wave models, it uses a point spectral growth mechanism, i.e., it applies the energy balance equation in a directionally integrated form. The directionality of its growth is obtained from an assumed spreading function on the wind direction. In this study, the energy balance equation is applied in directional form using directional atmospheric energy source functions. The B function of Miles’ instability mechanism is derived following the analysis of Phillips and it is tuned to the directionally integrated form used in the SOWM. Two infinite ocean wave models are used to compare the behavior of the point and directional growth mechanisms under various wind conditions. The directional form shows more flexibility in responding to directionally varying winds while the point spectral form creates excess energy spread widely over direction when operating in the presence of swell. / Ph. D. / incomplete_metadata