THE RADIOSOUNDINGS OF PAYERNE - ASPECTS OF THE SYNOPTIC-DYNAMIC CLIMATOLOGY OF THE WIND-FIELD NEAR MOUNTAIN-RANGES

Using routinely collected radiosounding data at Payerne, Switzerland, a climatological examination of the influence of the Alps on the atmosphere is undertaken. The vertical structure of the wind field up to 6 200 m asl is investigated at height intervals of 150 m. The channelling influence of the Alps is found to reach up to about, but not higher than, the 500 hPa level in the mean. Case studies illustrate selected examples of wind profiles and thus demonstrate the complexity and great variety of observed profiles. The problem of coupling/decoupling of different layers is discussed, and a simple classification scheme is proposed to classify wind profiles with respect to coupling or decoupling. It is found that roughly 2/3 of the profiles are decoupled. The scheme is also compared with the weather type classification of the "Alpenwetterstatistik" of Schuepp (1979).