Observations of Normal Pressure on Wind-Generated Sea Waves. Volume I,

摘要

A measurement system was designed and built which consists of a capacitance wire wave sensor on which a buoy carrying a pressure sensor slides vertically. This was used to obtain simultaneous quasi-Eulerian measurements of waves and the normal pressures on their surface. Pressure power spectra from all 6runs appear to consist of a 'basic'spectrum similar to that observed over land,on which is superimposed a wave-induced 'hump'which at low wave frequencies is simply the weight of air above the surface. At frequencies near the wave peak phases shifted from the -180degrees at lower frequencies by an amount which exceeds values predicted from Miles'theory by 20degrees. Spectra of the fluxes of energy and momentum from wind to waves are sharply peaked at a frequency at or (usually) slightly higher than the wave peak in contrast to the rather broad stress spectrum measured not far above the waves. Energy must be transferred to the lowest wave frequencies by a mechanism within the wave field itself. (Author)