A STUDY OF MESOSCALE FEATURES OF SUMMERTIME MINIMUM WIND FIELDS IN THE LOWER STRATOSPHERE.

Mesoscale observations of summertime minimum wind fields in the lower stratosphere disclose a complex mesostructure in the winds located between the stratospheric easterlies and tropospheric westerlies. Anticyclonic rotation of wind directions appears to predominate but speeds, although low, are highly variable. There are a number of layers, averaging 1000 ft thick, that have a speed of less than 10 kt. These layers seem to have no traceable continuity in time or space. There is evidence of significant inertial influence on winds of less than 10 kt. Two sets of data were obtained from radiosondes with extended power supplies carried on large plastic balloons that made slow ascents and descents through this region of the atmosphere. The success of these ventures supports the concept of using free-floating and tethered balloons as hovering or station-keeping vehicles. Author