Foehn wind
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A foehn wind or föhn wind is a type of dry downslope wind which occurs in the lee of a mountain range. It is a rain shadow wind which results from the subsequent adiabatic warming of air which has dropped most of its moisture on windward slopes (see orographic lift). As a consequence of the different adiabatic rates of moist and dry air, the air on the leeward slopes becomes warmer than equivalent elevations on the windward slopes. Föhn winds can raise temperatures by as much as 30°C (54°F) in just a matter of hours. Central Europe enjoys a warmer climate due to them.
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[edit] Effects
Winds of this type are called "snow-eaters" for their ability to make snow melt (also sublimate) rapidly. This ability is based not only on high temperature, but also the low relative humidity of the air mass.
Föhn winds are notorious among mountaineers in the Alps, especially those climbing the Eiger, for whom the winds add additional difficulty in ascending an already difficult peak.
They are also associated with the rapid spread of wildfires, making some regions which experience these winds particularly fire-prone.
These winds are often associated with illness ranging from migraines to psychosis. A study by the Ludwig-Maximilians-Universität München found that suicide and accidents increased by 10 percent during föhn winds in Central Europe. The causation of Föhnkrankheit (English: Föhn-sickness) is yet unproven. Labelling for preparations of aspirin combined with caffeine, codeine and the like will sometimes include Föhnkrankheit amongst the indications.
[edit] Etymology
The name föhn (from the German Föhn, pronounced [føːn]) originated in the alpine region. From Latin (ventus) favonius, a mild west wind of which Favonius was the Roman personification.[1]
[edit] Local examples
Regionally, these winds are known by many different names. These include:
- Zonda winds in Argentina
- Chinook winds in the Rocky Mountains, United States/Canada and the Chugach Mountains of Alaska, United States
- The Nor'wester in Hawkes Bay, Canterbury and Otago, New Zealand
- Föhn in Wollongong and South Coast, NSW Australia. Often associated with heavy Orographic Lifiting on the Windward Side of the Escarpment
- Halny in the Carpathian Mountains, Eastern Europe
- Fogony in the Catalan Pyrenees
- Bergwind in South Africa
- Viento Sur in the Cantabrian region (northern Spain)
- Terral in Málaga (southern Spain)
- Föhn in Austria, southern Germany and German-speaking regions of Switzerland
- The Helm wind, on the Pennines in the Eden Valley, Cumbria, England
[edit] In Popular Culture
- Peter Camenzind, a novel by Hermann Hesse refers, at length, to the Alpine Föhn.
- The föhn plays an important part in Dario Argento's film Phenomena.
[edit] Fön trademark
AEG registered the trademark Fön in the 1920s for its hairdryer, which is widely used as a synonym in several languages, such as German, Danish, Italian, Dutch, Norwegian, Romanian, Slovenian, Swedish, Turkish and French in western Switzerland.
[edit] See also
[edit] References
- McKnight, TL & Hess, Darrel (2000). Foehn/Chinoonk Winds. In , Physical Geography: A Landscape Appreciation, pp. 132. Upper Saddle River, NJ: Prentice Hall. ISBN 0130202630
[edit] Footnotes
- ^ Concise Oxford Dictionary, 10th edition, Oxford University Press, entry föhn.
