A FIELD INVESTIGATION OF AIR FLOW IMMEDIATELY ABOVE OCEAN SURFACE WAVES,
Abstract
Simultaneous measurements of wind velocity and water height were made on eleven days at an exposed site off the New England coast. While a wave gauge measured water height, a vertical array of anemometers recorded wind velocities at as many as eight heights up to 12 meters above mean sea level (MSL). The three lowest anemometers were arranged to float 30, 50 and 70 cm above the instantaneous water surface. Continuous atmospheric pressure and temperature measurements were made during several runs. An analysis of this data indicates that to a good first approximation, the horizontal wind velocity increases as a logarithmic function of height. Limited data from cross-correlations of pressure and wave indicate that at a height of 1 to 2 meters above MSL, the maximum pressure occurs near the trough. The measured energy transfer rate to the waves in a developing sea and the rate predicted by Miles' theory are in reasonable agreement. The averaging of data over long periods or making strong assumptions about the wind profile and its slope seriously degrade calculations based on Miles' theory. Short-term changes in wind velocity and the profile and shear stresses near or at the surface may be very important in the wave generation process. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- May 01, 1968
- Accession Number
- AD0670539
Entities
People
- John R. Seesholtz
Organizations
- Massachusetts Institute of Technology