Numerical prediction of the mean wind over water waves

Abstract

Stauffer (1973) developed a theoretical model for the prediction of air flow above ocean waves. In this study his results were extended with the addition of buoyance effects and two different lower boundary conditions. Through numerical solutions it was possible to determine that: 1) mean wind velocities at lower levels closely approximate the initial mean velocity profile for large wave numbers (k >/- 0.45 m(-1)) or small wave amplitudes, 2) mean wind velocities at lower levels fluctuate more from the initial mean velocity profile as the wave number decreased or the wave amplitude increases, 3) solutions were very sensitive to the level when the velocity gradient is computed in the lower boundary level where the velocity gradient is computed in the lower boundary condition, 4) disturbance potential temperature at lower levels increases inversely with wave number, and 5) the presence of temperature fluctuations has an insignificant effect on the Reynolds stress or on the stress function. The numerical solutions show general agreement with the observational analyses of wave modified wind profiles by Davidson (1976). However, these comparisons are not conclusive because of the sensitivity in the lower boundary condition.