An examination of the spectrum for coastal winds on the mesoscale

Wind speed data were taken at a weather station on the coast
and horizontal wind speed energy spectra were computed. The shape
of an average spectrum obtained in marine environment is compared
with an average land spectrum and the presence of a spectral gap is
observed in the shoreline spectrum. Wave number domain spectra
are compared with frequency domain spectra. Strong similarity
between the spectra is found for short periods, but at longer periods
the f-space spectrum localizes most of the energy at specific frequencies,
while the k-space spectrum spreads the energy over many
wave numbers. When the wind speed is fairly constant, Taylor's
hypothesis is found to be a reasonable approximation up to periods
of tens of minutes.
A preliminary investigation of the dependence of the value of
the drag coefficient on the period over which the average wind
is measured was made. A line of the form C[subscript Dx]/C[subscript Dā‚ā‚€]= .89 + .1 log X
fits the graphed points quite well with a correlation of .98, where X
is the averaging distance in miles. Differences of 20% in the value
of the drag coefficient over averaging distances between 10 and 1600
miles are observed. From this preliminary study, it appears that
a more detailed study of this effect would be worthwhile. / Graduation date: 1972

Identiferoai:union.ndltd.org:ORGSU/oai:ir.library.oregonstate.edu:1957/28402
Date09 June 1971
CreatorsFrye, Daniel Evan
ContributorsPond, Stephen
Source SetsOregon State University
Languageen_US
Detected LanguageEnglish
TypeThesis/Dissertation

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