Implementation of new experimental input/dissipation terms for modelling spectral evolution of wind waves

Numerical simulations of the wind-wave spectrum are conducted on the basis of the new wind input and wave dissipation functions obtained in the Lake George field experiment. This experiment allowed simultaneous measurements of the source functions in a broad range of conditions, including extreme wind-wave circumstances. Results of the experiment revealed new physical mechanisms in the processes of spectral input/dissipation of wave energy, which are presently not accounted for in wave forecast models. These results were parameterised as source terms in a form suitable for spectral wave models. The simulations were conducted by means of the two-dimensional research WAVETIME model with an exact solution for the nonlinear term. Physical constraints were imposed on the source functions in terms of the known experimental dependences for the total wind-wave momentum flux. Enforcing the constraints in the course of wave spectrum evolution allowed fine tuning of experimental parameters of the new input and dissipation functions. The resulting time-limited evolution of integral, spectral and directional wave properties, based on implementation of the new physically-justified source/sink terms and constraints, is then analysed. Good agreement of the simulated evolution with known experimental dependences is demonstrated.