WIND MEASUREMENTS NEAR THE SURFACE OF WAVES

Wind-over-wave in situ measurements are typically conducted in two different fashions: either by means of wave-riding buoys, or by placing anemometers well elevated above the surface. Routinely, concept of the constant-flux layer is invoked to convert one into another as necessary. In the paper, comparisons of mean wind speeds and wind-momentum fluxes are conducted, based on measurements throughout the wave boundary layer, including wave-follower measurements very near the surface. Significant deviations from the constant-flux expectations are found. Near the surface, the fluxes are less than those obtained by extrapolation within the logarithmic-layer assumption, and the mean wind speeds are correspondingly larger. Such results have significant implications for modelling the wind-generated waves and for calibrations of remotely sensed surface wind conditions.