The geographic position of the Vienna airport (Schwechat) with the Alps massif in the West occasionally promotes strong inhomogeneities of wind and temperature in the vertical or temporal domain. To identify and monitor such events in routine operation the Austrian Flight Control Board (ACG) decided to install in April 2013 a METEK Doppler SODAR PCS.2000-64 wind profiler with a 1290 MHz RASS extension for vertical wind and temperature profiling in height ranges of 50 … 500 m which are relevant during take-off or landing. Currently a 2-minutes refresh of the 10-minutes averages is developed for a later system upgrade. An example of significant inhomogeneities is shown as a time-height display.
Vertical shear of wind direction up to 120° within 300 m height difference was observed on 1st May 2013. A moderate NW wind flow prevailed near ground while the upper wind fields showed a fresh SW flow. The center of the shear layer descended from 450 m to 250 m height within 5 hours while the wind speed calmed down near ground.