EFFECTS OF SEA MATURITY ON SATELLITE ALTIMETER MEASUREMENTS

For equilibrium and near-equilibrium sea states, the wave slope variance is a function of wind speed U and of the sea maturity. The influence of both factors on the altimeter measurements of wind speed, wave height, and radar cross section σ° is studied experimentally. The necessary theoretical background, both on wave statistics and on the near-nadir radar backscatter is outlined. It is based on a recently proposed view that the effective fractal dimension for a surface patch corresponding to the equilibrium range of wave spectra increases as the wave field matures. The experimental part is based on 1 year's worth of Geosat altimeter observations colocated with in situ wind and wave measurements by 20 NOAA buoys. -from Authors