  A systematic and full description of the theory for a dissipation mechanism
of wind wave energy in a spectral representation is given. As a basis of the
theory, the fundamental is stated that the most general dissipation mechanism
for wind waves is provided by the viscosity due to interaction between wave
motions and turbulence of the water upper layer. The latter, in turn, is
supposed to be induced by the whole aggregate of dissipation processes taking
place at the air-sea interface. In the frame of phenomenological constructions
of nonlinear closure for Reynolds stresses, it is shown that the dissipation
function is generally a power series with respect to wave spectrum, starting
from a quadratic term. Attracting previous results of the author, a simplified
parameterization of the general theoretical result is done. Physical meaning
for parameters of the dissipation function and its compliance with the new
experimental facts established in this field for the last 5-10 years is
discussed. Summarized theoretical results were verified in the mathematical
shells of the well known numerical models for wind waves, WAM and WAEWATCH.
Evidence is given, illustrating a superiority of the proposed model
modifications. Prospects for elaboration of the theory are discussed.
