Zonda wind (in Spanish, viento zonda) is a regional term for the föhn wind that often occurs on the eastern slope of the Andes, in Argentina. The Zonda is a dry wind (often carrying dust) which comes from the polar maritime air, warmed by descent from the crest, which is some 6,000 m (18,000 ft) above sea level. It may exceed a velocity of 40 km/h (25 mph). A föhn wind or foehn wind occurs when a deep layer of prevailing wind is forced over a mountain range (Orographic lifting). ... This article or section does not adequately cite its references or sources. ... Planes view of the Andes, Peru. ... Amundsen-Scott South Pole Station. ... This article does not cite any references or sources. ... The metre (or meter, see spelling differences) is a measure of length. ... A foot (plural: feet or foot;[1] symbol or abbreviation: ft or, sometimes, ′ – a prime) is a unit of length, in a number of different systems, including English units, Imperial units, and United States customary units. ... For considerations of sea level change, in particular rise associated with possible global warming, see sea level rise. ... Kilometre per hour (American spelling: kilometer per hour) is a unit of both speed (scalar) and velocity (vector). ... Miles per hour is a unit of speed, expressing the number of international miles covered per hour. ...

While this type of föhn wind may occur over most central parts of western Argentina, its effects are more impressive in La Rioja, San Juan, and northern Mendoza provinces, because the mountain barrier (the Andes) is higher, while to the north the Puna plateau dissipates these winds. La Rioja is a one of the provinces of Argentina and is, located in the west of the country. ... San Juan is a province of Argentina, located in the westen part of the country. ... Mendoza is one of the 23 provinces of Argentina, located in the western central part of the country in the Cuyo region. ... Puno, Peru, is one of larger cities of the Altiplano. ...

The Zonda wind is basically produced by the northeastward movement of polar fronts, and although is hot and dry at the low-lands, it is the main mechanism for snow precipitation at the high altitude chains, where it looks as viento blanco, reaching speeds sometimes over 200 km/h. Thus, instead of being a snow-eater, this wind is particularly important for this arid region, as it is connected to the buildup of the winter snow cover and accumulation over the scarce local glaciers. Animation of snowcover changing with the seasons Trees covered with snow Snow covering a leaf. ... An arid environment has an extremely low yearly precipitation, receiving much less rain or snowfall annually than would satisfy the climatological demand for evaporation and transpiration. ... A glacier is a large, persistent body of ice, formed largely of compacted layers of snow, that slowly deforms and flows in response to gravity. ...

According to studies (conducted over the period 1967–1976), the Zonda wind most commonly starts during the afternoon (between 12 and 6 PM), and tends to last between 1 and 12 hours, though it may present itself intermitently for as long as 2 or 3 days. It is countered usually by the entrance of cold air masses moving northwestward (viento sur). In 90% of the cases, the phenomenon takes place between May and November.

Alternative usage

The term zonda also describes a hot, humid north wind in the Pampas, in advance of a depression moving eastwards, and preceding the pampero. This wind is also called the sondo. The pampas (from Quechua for plain) are the fertile lowlands that extend across c. ... The pampero is a west or southwest wind in Southern Argentina. ...

References

• (Spanish) MeteoBlogs — Viento Zonda. National Meteorological Service, Air Regions Command, Argentine Air Force.
• "The land where blows el Zonda". Article.