Wind Measurements Near the Surface of Waves

Wind-over-wave in situ measurements are typically conducted in two different fashions: either by means of waveriding 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 logarithmiclayer 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.