ATMOSPHERIC TURBULENCE MEASUREMENTS AND ANALYSIS

Abstract

Satisfactory measuring techniques have been developed which overcome the four, principal experimental problems arising in the investigation of atmospheric turbulence. 1. The data are made reproducible for statistical analysis by recording them on a portable magnetic tape recorder. 2. and 3. The problems of measuring wind velocity fluctuations over broad ranges (frequencies between 0 and 50 cycles per second, and magnitudes between 0.25 and 20 meters per second) are solved by using hot-wire anemometers together with non-linear amplifiers. 4. Measurements at elevations up to several hundred meters are made feasible by the use of a multi-cable tethering system for a balloon which supports the measuring devices. The techniques permit the measurement of velocity distributions, frequency spectra, autocorrelation coefficients, and heat flux at any elevation. The difficulty of constructing such measuring and analysis equipment is balanced by the relative simplicity with which a complete statistical analysis of the data may be performed.