Zonda (wind)

Zonda is a regional name for a foehn wind from the west that is widespread in the eastern Andean region of Argentina . The foehn wind that comes from the opposite direction is known as Puelche in Chile .

Also called Zonda or Sondo is a warm, humid north wind of the pampas , which is caused by a low pressure area moving eastwards over them .

Characteristic

The foehn wind Zonda is a dry and often dust-bearing wind from the direction of the maritime polar air . In the course of the drop in altitude from the Andes ridge (approx. 6000  m ) to regions further down, the air mass heats up adiabatically and can reach wind speeds of over 40 km / h.

Although the Zonda occurs almost everywhere in western Argentina, its effects are greatest in the provinces of La Rioja , San Juan and in the north of Mendoza , since these are where the difference in altitude to the Andean ridge is greatest.

Emergence

The Zonda is created by a northeasterly movement of the polar fronts. In the lowlands it arrives hot and dry, in the higher regions, where it is known as viento blanco (white wind) and can reach speeds of up to 200 km / h, it is the main mechanism for snow.

According to studies from 1967 to 1976, the Zonda occurs 90% of the time between May and November. It usually begins between noon and 6 pm and lasts between one and twelve hours; but it can also last up to two or three days.

See also: winches and wind systems