Vertical Wind Component Estimates up to 1.2 km above Ground

Abstract

Vertical wind components were computed up to 1.2 km from 37 wintertime and 10 summertime balloon observations between 0900 and 1200 local time utilizing the accurate and high-resolution cinetheodolite/Jimsphere system. The mean ascent rate of the Jimsphere was computed from all observations taken on a particular day. The ascent rate was found to be 5.16 m sec?1 for the winter and 5.10 m sec?1 for the summer months. The individual variations of a given observation from the mean ascent rate were assumed to be the vertical component. Variations in balloon ascent caused by variation in drag, anomalous variation in atmospheric density, balloon response to the wind, and aerodynamically induced motions are discussed. Vertical wind components ranged from 10?25 cm sec?1 in a stable atmosphere and 55?100 cm sec?1 under unstable conditions depending on wind speed.