Articles | Volume 46, issue 1
31 Mar 1991
 | 31 Mar 1991

Nebelkarten der Schweiz

F. Troxler and H. Wanner

Abstract. The analysis of fog distribution over Switzerland consists of two different studies:
The first deals with the spatial determination of fog frequencies and fog types for the early morning. It was realized by using the daily observations of 320 stations. This point by point information was spatially interpolated with the aid ofthe information (mean fog cover frequency) of 94 typical fog distributions detected from NOAA satellite data. The derived fog map of Switzerland includes four different fog zones: ground fog zone, fog-free intermediary and high fog (stratus) zone, fog-free slope zone, lower up-slope fog zone.
The result of the second study consists of four maps showing the fog cover frequency of the important weather types with fog layers over the Swiss Alpine foreland. They were traced out by using the above mentioned satellite data. The four maps indicate clearly that the fog and cold air distribution during anticyclonic weather situations is strongly determined by the sub-synoptic pressure and wind field.