FLUCTUATIONS OF ATMOSPHERIC TEMPERATURE AS A MEASURE OF THE SCALE AND INTENSITY OF TURBULENCE NEAR THE EARTH'S SURFACE

Abstract

This study summarizes certain preliminary observations on the structure of turbulence near the earth's surface. An array of sensitive bead thermistors is used to measure temperature or temperature-difference fluctuations simultaneously at a number of points. The resulting scale or average size of the turbulence-produced atmospheric inhomogeneities is then determined from such analyses as (a) the functional form of the auto-correlation coefficient versus time delay, (b) the rate at which the cross-correlation between respective temperature-fluctuation recordings varies with element separation, and (c) the rate at which the root-mean-square value of the temperature-difference recordings varies with element separation. For the surface under consideration, the scale of turbulence at a height of three feet above the ground varies from about 3 to 15 ft, with the downwind dimension greater than the crosswind dimension.