COMPARISON OF JIMSPHERE AND RAWINSONDE WIND SHEARS
CONTROL DATA CORP MINNEAPOLIS MN RESEARCH DIV
Pagination or Media Count:
Characteristics of the wind shear for 25 meter layers were prepared from a series of 175 detailed wind ascents to 18 km taken with a Jimsphere balloon followed by FPS-16 radar from November 1964 to June 1965. To determine how well the shears for small layers could be estimated from rawinsonde data, two new sets of ascents were created from the original Jimsphere data. One set consisted of wind data at 23 levels corresponding only to standard pressure levels, and the other set at the 46 minute levels at which winds are reported on observational forms. The differences in results were thus due only to the differing vertical resolution in the three series. The results showed that the magnitudes of the mean pressure and minute shears for 25 meters are smoothed to about 13 and 12 respectively of the Jimsphere shears. Graphs of corrections for pressure and minute data needed to approximate the Jimsphere shear are presented both in terms of thickness of layer, and, for 25 m as a function of height. The mean Jimsphere shear for a 25 meter layer increases from 0.3 msec at the lowest levels to 0.5 at 11 km and to 0.8 at 17 km, with a standard deviation of about 70 of the mean.