Accession Number : AD0853299

Title :   Low Altitude Atmospheric Turbulence Lo-Locat Phases I and II.

Descriptive Note : Final rept. 15 Apr 66-19 Aug 68,

Corporate Author : BOEING WICHITA CO KS

Personal Author(s) : Gunter, D. E. ; Jones, G. W. ; Jones, J. W. ; Monson, K. R.

Report Date : FEB 1969

Pagination or Media Count : 421

Abstract : The report presents procedures, analysis methods, and final results pertaining to the LO-LOCAT Program (Phases I and II). Approximately 800 hours of low-level (0-1,000 feet) turbulence and associated meteorological data recorded from September 15, 1966 to December 20, 1967 are analyzed. A model of the turbulence environment at low-level is presented in terms of gust velocity primary peaks, amplitude samples, rms values, maximum values, and derived equivalent gusts. Mathematical expressions of turbulence spectra and scale length statistics, and correlations between atmospheric gust velocities and meteorological and geophysical phenomena are shown. The frequency spectrum of turbulence and the associated characteristics of isotropy, homogeneity, and stationarity are discussed. It was found that gust velocity magnitude rms values above 1.0 fps may be approximated by truncated normal distributions. For wavelengths less than 7,000 feet turbulence spectra are best represented by the von Karman expressions. The longitudinal scale length of atmospheric turbulence at low altitude is approximately 400 feet. The turbulence, sampled during 5-1/2 minutes over a distance of approximately 21 miles, at absolute altitudes below 1,000 feet, was found to be stationary, isotropic, and homogeneous. (Author)

Descriptors :   (*CLEAR AIR TURBULENCE, LOW ALTITUDE), STATISTICAL ANALYSIS, WIND, VELOCITY, GUSTS, MATHEMATICAL MODELS, POWER SPECTRA, TURBULENCE, CORRELATION TECHNIQUES, ATMOSPHERIC MOTION, MOUNTAINS, ISOTROPISM, FREQUENCY, TACTICAL AIR SUPPORT.

Subject Categories : Atmospheric Physics

Distribution Statement : APPROVED FOR PUBLIC RELEASE