CLIMATOLOGY OF NORTH FÖHN IN CANTON TICINO AND WESTERN LOMBARDY CLIMATOLOGIA DEL FÖHN SETTENTRIONALE IN CANTON TICINO E IN LOMBARDIA OCCIDENTALE

• Main Authors: Paolo Ambrosetti, Luigi Mariani, Piero Scioli
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Subjects: catabatic wind; Alps; climatology; climatic change; weather types; North Atlantic Oscillation (NAO; Monti; North Atlantic; North Atlantic oscillation
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.579.4645; http://www.agrometeorologia.it/documenti/rivista10_02/ambrosetti.pdf

The analysis of yearly, seasonal and monthly frequency of north föhn in the Po valley was carried out considering some stations located in western Lombardy (Italy) and in Canton Ticino (Switzerland) and adopting synoptic, mesoscale and punctual (single station’s) recognition criteria. The results show a gradual reduction of föhn frequency with increasing dis-tance from the Alpine watershed but a relevant presence of this wind is shown also in the low plain. A simple linear model able to describe the mean number of days with föhn on the Southern of the Alps as a function of the distance from the Al-pine watershed is also discussed. A change point in 1988 was detected by means of the statistical analysis of föhn time se-ries of Locarno-Monti; this change point is coherent with discontinuities in other climatic variables detected by other au-thors and that can be seen as symptoms of a climatic change happened in Europe in ’80 years of XXth century. The time series 1988-2003 present a reduction of föhn yearly events with a parallel increase of the Winter percentage contribution to the yearly total