Altitudinal zones of Alps mountains-extended diagram

The climate of the Alps is the

climate Climate is the long-term weather pattern in an area, typically averaged over 30 years. More rigorously, it is the mean and variability of meteorological variables over a time spanning from months to millions of years. Some of the meteorologi ...

, or average

weather Weather is the state of the atmosphere, describing for example the degree to which it is hot or cold, wet or dry, calm or stormy, clear or cloud cover, cloudy. On Earth, most weather phenomena occur in the lowest layer of the planet's atmos ...

conditions over a long period of time, of the exact middle Alpine region of

Europe Europe is a large peninsula conventionally considered a continent in its own right because of its great physical size and the weight of its history and traditions. Europe is also considered a subcontinent of Eurasia and it is located entirel ...

. As air rises from

sea level Mean sea level (MSL, often shortened to sea level) is an average surface level of one or more among Earth's coastal bodies of water from which heights such as elevation may be measured. The global MSL is a type of vertical datuma standardise ...

to the upper regions of the atmosphere the

temperature Temperature is a physical quantity that expresses quantitatively the perceptions of hotness and coldness. Temperature is measurement, measured with a thermometer. Thermometers are calibrated in various Conversion of units of temperature, temp ...

decreases. The effect of

mountain A mountain is an elevated portion of the Earth's crust, generally with steep sides that show significant exposed bedrock. Although definitions vary, a mountain may differ from a plateau in having a limited summit area, and is usually highe ...

topography on prevailing

wind Wind is the natural movement of air or other gases relative to a planet's surface. Winds occur on a range of scales, from thunderstorm flows lasting tens of minutes, to local breezes generated by heating of land surfaces and lasting a few ho ...

s is to force warm air from the lower region into an upper zone where it expands in

volume Volume is a measure of occupied three-dimensional space. It is often quantified numerically using SI derived units (such as the cubic metre and litre) or by various imperial or US customary units (such as the gallon, quart, cubic inch). Th ...

at the cost of a proportionate loss of

heat In thermodynamics, heat is defined as the form of energy crossing the boundary of a thermodynamic system by virtue of a temperature difference across the boundary. A thermodynamic system does not ''contain'' heat. Nevertheless, the term is ...

, often accompanied by the

precipitation In meteorology, precipitation is any product of the condensation of atmospheric water vapor that falls under gravitational pull from clouds. The main forms of precipitation include drizzle, rain, sleet, snow, ice pellets, graupel and hail. ...

of moisture in the form of

snow Snow comprises individual ice crystals that grow while suspended in the atmosphere—usually within clouds—and then fall, accumulating on the ground where they undergo further changes. It consists of frozen crystalline water throughout ...

rain Rain is water droplets that have condensed from atmospheric water vapor and then fall under gravity. Rain is a major component of the water cycle and is responsible for depositing most of the fresh water on the Earth. It provides water ...

or hail.

Climate as a function of elevation

Because air cools as it rises, the climate of the Alps is strongly dependent on the elevation. The Alps contain a number of different kinds of climate zones, by elevation. These zones can be described by the

Köppen climate classification The Köppen climate classification is one of the most widely used climate classification systems. It was first published by German-Russian climatologist Wladimir Köppen (1846–1940) in 1884, with several later modifications by Köppen, notabl ...

, and also correspond to the biotic zones of the Alps. Up to approximately of elevation, the climate is classified as

oceanic Oceanic may refer to: *Of or relating to the ocean *Of or relating to Oceania **Oceanic climate **Oceanic languages **Oceanic person or people, also called "Pacific Islander(s)" Places * Oceanic, British Columbia, a settlement on Smith Island, ...

or Cfb under the Köppen system. Like much of lowland northern Europe, the summers are mild and the winters are cool, but not cold. The climate is moderated by proximity to the

Atlantic Ocean The Atlantic Ocean is the second-largest of the world's five oceans, with an area of about . It covers approximately 20% of Earth's surface and about 29% of its water surface area. It is known to separate the " Old World" of Africa, Europe ...

. The climate creates the colline biotic zone in the lowlands, which is characterized by the

deciduous forest In the fields of horticulture and Botany, the term ''deciduous'' () means "falling off at maturity" and "tending to fall off", in reference to trees and shrubs that seasonally shed leaves, usually in the autumn; to the shedding of petals, ...

of the

Western European broadleaf forests The Western European broadleaf forests is an ecoregion in Western Europe, and parts of the Alps. It comprises temperate broadleaf and mixed forests, that cover large areas of France, Germany and the Czech Republic and more moderately sized parts ...

ecoregion. Between approximately , the climate changes to either a

humid continental climate A humid continental climate is a climatic region defined by Russo-German climatologist Wladimir Köppen in 1900, typified by four distinct seasons and large seasonal temperature differences, with warm to hot (and often humid) summers and freezing ...

(Dfb under the Köppen system), or a Cfc oceanic climate, depending on location. As elevation increases, the winters become colder and the summers become shorter. A mixture of conifer and

deciduous In the fields of horticulture and Botany, the term ''deciduous'' () means "falling off at maturity" and "tending to fall off", in reference to trees and shrubs that seasonally shed leaves, usually in the autumn; to the shedding of petals, ...

trees occupy this montane zone, leading to a change in ecoregion to Alps conifer and mixed forests. Between approximately , the climate becomes subarctic (Dfc under the Köppen system), with even shorter summers. The shorter growing season shifts the

forest A forest is an area of land dominated by trees. Hundreds of definitions of forest are used throughout the world, incorporating factors such as tree density, tree height, land use, legal standing, and ecological function. The United Nations' ...

to be purely coniferous. At about , the climate becomes too cold to support trees, and is classified as an

alpine climate Alpine climate is the typical weather (climate) for elevations above the tree line, where trees fail to grow due to cold. This climate is also referred to as a mountain climate or highland climate. Definition There are multiple definitions o ...

(ET under the Köppen system). The summers become cool and only grasses and low plants are adapted to grow. This alpine climate extends to approximately . Above approximately , the climate transitions to an

ice cap climate An ice cap climate is a polar climate where no mean monthly temperature exceeds . The climate covers areas in or near the high latitudes (65° latitude) to polar regions (70–90° north and south latitude), such as Antarctica, some of the northe ...

, where the mean temperature is always below . At these altitudes, no plants can grow and the ground is either rock or ice.

References

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Alps The Alps () ; german: Alpen ; it, Alpi ; rm, Alps ; sl, Alpe . are the highest and most extensive mountain range system that lies entirely in Europe, stretching approximately across seven Alpine countries (from west to east): France, Swi ...

Alps Ecology of the Alps