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Numerical simulations of the wind-wave spectrum evolution are conducted by means of new observationbased 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 features had been parameterized as source terms in a form suitable for spectral wave models; in the present study, they were tested, calibrated, and validated on the basis of such a model. Physical constraints were imposed on the source functions in terms of the known experimental dependences for the total wind-wave momentum flux and for the ratio between the total input and total dissipation. Enforcing the constraints in the course of wave-spectrum evolution allowed calibration of the free experimental parameters of the new input (Part I of the study) and dissipation functions; the latter is the topic of the present paper. The approach allows separate calibration of the source functions before they are employed in the evolution tests. The evolution simulations were conducted by means of the one-dimensional research WAVETIME model with an exact solution for the nonlinear term. 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 analyzed. Good agreement of the simulated evolution with known experimental dependences is demonstrated.

This paper is dedicated to the investigation and calibration of the parameterized form for the wind-input source term Sin proposed earlier on the basis of field observations at Lake George, Australia. The main objective of this study was to obtain spectral forms for the wind-input source function Sin, which incorporates the novel observation-based features and at the same time satisfies the important physical constraint that the total integrated wind input must agree with independently observed magnitudes of the wind stress. Within this approach, a new methodology, a dynamic self-adjusting routine, was developed for correction of the windinput source function Sin. This correction involves a frequency-dependent adjustment to the growth rate g(f), based on extrapolations from field data. The model results also show that light winds require higher-rate adjustments of the wind input than strong winds.