Accession Number : AD0431669

Title :   SPECTRA OF LAKE ERIE WATER LEVELS,

Corporate Author : CHICAGO UNIV ILL

Personal Author(s) : Platzman,George W. ; Rao,Desiraju B.

Report Date : OCT 1963

Pagination or Media Count : 35

Abstract : Variance and covariance spectra of Lake Erie hourly scaled water levels are analyzed with resolution 0.1 cycles per day (in some instances 0.05 cpd) in the frequency range 0 to 8 cpd for thirteen stations in the six-month summer period April through September 1958, and for some of these stations in the six-month winter period October 1958 through March 1959. The main contribution to variance spectra at most stations is the range 0 to 1 cpd. Inherent noise levels are between 10,000 and .001 sq. ft./cycles per day; scaling noise is at most about .0001 sq. ft./cycles per day. The most conspicuous features of summer variance spectra are strong and consistent peaks near 1.7 cpd (14.1 hr), 2.6 cpd (9.2 hr), 4.0 cpd (6.0 hr), and 5.8 cpd (4.1 hr), which correspond to the first four modes of longitudinal free oscillation of the Lake. A diurnal peak appears consistently in analysis with 0.1 cpd resolution; with 0.05 cpd resolution a distinct semi-diurnal peak emerges at 1.95 cpd (12.3 hr). Covariance spectra give phases consistent with the hypothesis that the fundamental mode of oscillation is an amphidromic Kelvin-type wave, in which there is counterclockwise rotation of the phase of high water. (Author)

Descriptors :   (*LAKE WAVES, OSCILLATION), LAKES, MATHEMATICAL ANALYSIS, MEASURING INSTRUMENTS, OSCILLATION, MEASUREMENT, NOISE, LIQUID LEVEL GAGES, UNDERWATER SOUND

Distribution Statement : APPROVED FOR PUBLIC RELEASE