On the base of laboratory experiments on co- and cross-polarized microwave signal scattering on a wavy water surface, the dependences of NRCS on wind speed and friction velocity at high wind speeds were obtained. It is shown that the cross-polarized NRCS demonstrates sensitivity to the wind speed when its value is more than 20 m/s, in contrast to the co-polarized NRCS. Based on the analysis of the Doppler spectra, it was suggested that the backscattered signal is formed mainly on wave breakers. This assumption was verified by analyzing the dependence of the scattered signal power at both polarizations on the area of the white-cap coverage, which revealed their direct dependence. Based on the phenomenological approach used in statistical physics, a parametrization of the dependence of the white-cap coverage fraction on the wind friction velocity was proposed. This parametrization was based on the use of the universal Gibbs method, the central concept of which is a canonical ensemble or an ensemble of a thermodynamic system states which are in a weak thermal contact with a "thermostat". In this case, the atmospheric boundary layer acts as a thermostat, and the entire ensemble of states of the sea surface, including breakers, is the canonical ensemble. Based on this parametrization, the GMF was proposed to retrieve the wind speed and wind friction velocity for wind speeds above 40 m/s, which also considering the angular dependence of the NRCS.
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