Alpine climate

White Mountain, an alpine environment at 4,300 metres (14,000 ft) in California

For the climate of the mountains named the Alps, see Climate of the Alps.

Alpine climate is the average weather (climate) for a region above the tree line. This climate is also referred to as mountain climate or highland climate.

In the Köppen climate classification the alpine climate is part of "Group E," along with the polar climate, where no month has a mean temperature higher than 10 °C (50 °F).^[1] Certain highland climates can also fit under hemiboreal climate or Semi-arid climate groups of climate classification.

Description

The climate becomes colder at high elevations—this characteristic is described by the lapse rate of air: air tends to get colder as it rises, since it expands. The dry adiabatic lapse rate is 10 °C per km of elevation or altitude.^[2] Therefore, moving up 100 meters on a mountain is roughly equivalent to moving 80 kilometers (45 miles or 0.75° of latitude) towards the pole.^[3] This relationship is only approximate, however, since local factors such as proximity to oceans can drastically modify the climate.^[4] The main form of precipitation is often snow, often accompanied by stronger winds.

Distribution

The Cascade Mountains, the Rocky Mountains, the Alps, the Pyrenees and Sierra Nevada, the Andes, the Himalayas, the Tibetan Plateau, the Eastern Highlands of Africa, and the central parts of Borneo and New Guinea are examples of highland climates. The mountain climate in the Northern Andes is particularly known for the notion of four zones of elevation:

• Tierra caliente or hot land
• Tierra templada or temperate land
• Tierra fria or cold land
• Tierra helada or frozen land

In mountainous areas with alpine climate, the dominant biome is alpine tundra.

References

1. ^ McKnight, Tom L; Hess, Darrel (2000). "Climate Zones and Types: The Köppen System". Physical Geography: A Landscape Appreciation. Upper Saddle River, NJ: Prentice Hall. pp. 235–7. ISBN 0-13-020263-0. 
2. ^ "Adiabatic Lapse Rate". Goldbook. IUPAC. http://goldbook.iupac.org/A00144.html. 
3. ^ "Mountain Environments". United Nations Environment Programme World Conservation Monitoring Centre. http://quin.unep-wcmc.org/mountains/mountain_watch/pdfs/mountainEnvironments.pdf. 
4. ^ "Factors affecting climate". The United Kingdom Environmental Change Network. http://www.ecn.ac.uk/Education/factors_affecting_climate.htm. 

See also

• Alpine plant
• Alpine flora
• Climate of the Alps
• Köppen climate classification