Fluctuations of horizontal wind speed near the ground in convective conditions

Simultaneous records of temperature fluctuations and wind speed at several heights have been obtained with instruments suspended from captive balloons flying 225 m above level, uniform land. Variations in the horizontal wind speed near the ground appear to be associated with bursts of temperature fluctuation at heights of more than about 100 m in a way which suggests that convective plumes, or ‘thermals,’ become organized within the lowest few metres of the atmosphere.