Wind Shear for Small Thickness Layers

Abstract

Wind shear in the lowest 10,000 it of the atmosphere was investigated utilizing two or more cinetheodolites (Contraves cameras) tracking a smooth spherical 100-gm balloon. These data indicate that a simple power law relationship exists between 1) layer thickness and the magnitude of the vector shear, 2) layer thickness and the magnitude of the mean extreme vector shell, and 3) magnitude of the mean shear and standard deviation for given layers. From this relationship it appear that wind shears for small layers (50, 100, 200 ft) may be derived from wind values obtained over large shear intervals (1000, 2000, 3000 ft) with present operational equipment such as the GMD-1. A relationship exists between wind speed and wind shear for various shear intervals such that as the wind speed increases to 30?40 ft sec?1, the mean shear increases; the shear decreases for higher wind speeds.