- Foehn wind
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 lapse rates of moist and dry air, the air on the leeward slopes becomes warmer than equivalent elevations on the windward slopes. Föhn winds can raisetemperature s by as much as 30°C (54°F) in just a matter of hours.Central Europe enjoys a warmer climate due to the Föhn.Effects
Winds of this type are called "snow-eaters" for their ability to make
snow melt (alsosublimate ) rapidly. This snow-removing ability is caused not only by warmer temperatures, but also the low relativehumidity of the air mass, having been stripped of moisture by orographic precipitation coming over the mountain(s).Föhn winds are notorious among
mountaineer s in the Alps, especially those climbing theEiger , for whom the winds add additional difficulty in ascending an already difficult peak.They are also associated with the rapid spread of
wildfire s, 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 ofFöhnkrankheit (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.Etymology
The name "föhn" (from the German "Föhn", pronounced IPA| [føːn] ) originated in the alpine region. From Latin "(ventus) favonius", a mild west wind of which Favonius was the Roman personification. ["Concise Oxford Dictionary", 10th edition, Oxford University Press, entry "föhn".]
Local examples
Regionally, these winds are known by many different names. These include:
*Zonda wind s inArgentina
*Chinook wind s in theRocky Mountains ,United States /Canada and theChugach Mountains ofAlaska , United States
*The Nor'wester inHawkes Bay ,Canterbury andOtago ,New Zealand
*Föhn inWollongong andSouth Coast , NSW Australia. Often associated with heavyorographic lifiting on the windward side of the escarpment
*Halny in theCarpathian Mountains , Eastern Europe
*Fogony in the CatalanPyrenees
*Bergwind inSouth Africa
*"Viento del Sur" ("Southern Wind") in the Cantabrian region (northernSpain )
*Terral inMálaga (southernSpain )
*Föhn inAustria , southernGermany , German-speaking regions ofSwitzerland andNorthern Italy (even non German-speaking regions)
*Favonio in Ticino and Italy
*TheHelm wind , on thePennines in theEden Valley ,Cumbria ,England In Popular Culture
*"
Peter Camenzind ", a novel byHermann Hesse refers, at length, to the Alpine "Föhn".
* The föhn plays an important part inDario Argento 's film "Phenomena".
* The Föhn is used for the letter F in "Crazy ABC's" from the album "Snacktime! " by theBarenaked Ladies .
* The threat of the Föhn drives the protaganists Ayla and Jondalar inJean M. Auel 's The Plains Of Passage over a glacier before the spring melt. The pair make refereces to the mood altering phenomena of the wind, similar to those of theSanta Ana wind .Fön trademark
AEG registered the trademark "Fön" in the1920s for itshairdryer , which is widely used as asynonym in several languages, such as German, Swiss German, Danish, Italian, Dutch, Norwegian, Czech, Latvian, Romanian, Slovak, Slovenian, Swedish, Turkish and French in western Switzerland.ee also
*
Katabatic wind s
*Rain shadow 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
Footnotes
External links
* [http://www.bom.gov.au/lam/glossary/fpagegl.shtml#fo Illustration]
* [http://www.flickr.com/photos/snowfactory/2756402718/ Movie of a Foehn situation in the Swiss Alps]
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