A Proposed Spectral Form for Fully Developed Wind Seas Based on the Similarity Theory of S. A. Kitaigorodskii
Abstract
The data for the spectra of fully developed seas obtained for wind speeds from 20 to 40 knots as measured by anemometers on two weather ships are used to test the similarity hypothesis and the idea that, when plotted in a certain dimensionless way, the power spectra for all fully developed seas should be of the same shape as proposed by Kitaigorodskii (1961). Over the important range of frequencies that define the total variance of the spectrum within a few percent, the transformed plots yield a non-dimensional spectral form that is nearly the same over this entire range of wind speeds within the present accuracies of the data. However, since slight variations of the wind speed have large effects on the location of this non-dimensional spectral form, inaccuracies in the determination of the wind speed at sea allow for some latitude in the final choice of the form of the spectrum. Also since the winds used to obtain the non-dimensional form were measured at a height greater than ten meters, the problem of relating the spectral form to a standard anemometer height arises. The variability introduced by this factor needs to be considered. The results, when errors in the wind speed, the sampling variability of the data, and the anemometer heights are considered, suggest a spectral form that is a compromise between the various proposed spectra and that has features similar to many of them.
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 01, 1963
- Accession Number
- AD0421610
Entities
People
- Lionel Moskowitz
- Willard J. Pierson Jr.
Organizations
- New York University