Digital elevation modelA digital elevation model (DEM) or digital surface model (DSM) is a 3D computer graphics representation of elevation data to represent terrain or overlaying objects, commonly of a planet, moon, or asteroid. A "global DEM" refers to a discrete global grid. DEMs are used often in geographic information systems (GIS), and are the most common basis for digitally produced relief maps. A digital terrain model (DTM) represents specifically the ground surface while DEM and DSM may represent tree top canopy or building roofs.
ElevationThe elevation of a geographic location is its height above or below a fixed reference point, most commonly a reference geoid, a mathematical model of the Earth's sea level as an equipotential gravitational surface (see Geodetic datum § Vertical datum). The term elevation is mainly used when referring to points on the Earth's surface, while altitude or geopotential height is used for points above the surface, such as an aircraft in flight or a spacecraft in orbit, and depth is used for points below the surface.
Eastern AlpsEastern Alps is the name given to the eastern half of the Alps, usually defined as the area east of a line from Lake Constance and the Alpine Rhine valley up to the Splügen Pass at the Alpine divide and down the Liro River to Lake Como in the south. The peaks and mountain passes are lower than the Western Alps, while the range itself is broader and less arched.
Background radiationBackground radiation is a measure of the level of ionizing radiation present in the environment at a particular location which is not due to deliberate introduction of radiation sources. Background radiation originates from a variety of sources, both natural and artificial. These include both cosmic radiation and environmental radioactivity from naturally occurring radioactive materials (such as radon and radium), as well as man-made medical X-rays, fallout from nuclear weapons testing and nuclear accidents.
Cloud coverCloud cover (also known as cloudiness, cloudage, or cloud amount) refers to the fraction of the sky obscured by clouds on average when observed from a particular location. Okta is the usual unit for measurement of the cloud cover. The cloud cover is correlated to the sunshine duration as the least cloudy locales are the sunniest ones while the cloudiest areas are the least sunny places, as clouds can block sunlight, especially on sunrise and sunset where sunlight is already limited. The global cloud cover averages around 0.
Forest coverForest cover is the amount of forest that covers a particular area of land. It may be measured as relative (in percent) or absolute (in square kilometres/square miles). Nearly a third of the world's land surface is covered with forest, with closed-canopy forest accounting for 4 - 5 billion hectares of land. Forests provide many ecosystem services that humans and animals cannot survive without, but anthropogenic actions and climate change are threatening global forest cover in potentially irreversible ways.
AlpsThe Alps (ælps) are the highest and most extensive mountain range that is entirely in Europe, stretching approximately across eight Alpine countries (from west to east): Monaco, France, Switzerland, Italy, Liechtenstein, Germany, Slovenia, and Austria. The Alpine arch extends from Nice on the western Mediterranean to Trieste on the Adriatic and Vienna at the beginning of the Pannonian Basin. The mountains were formed over tens of millions of years as the African and Eurasian tectonic plates collided.
CloudIn meteorology, a cloud is an aerosol consisting of a visible mass of miniature liquid droplets, frozen crystals, or other particles suspended in the atmosphere of a planetary body or similar space. Water or various other chemicals may compose the droplets and crystals. On Earth, clouds are formed as a result of saturation of the air when it is cooled to its dew point, or when it gains sufficient moisture (usually in the form of water vapor) from an adjacent source to raise the dew point to the ambient temperature.
Outgoing longwave radiationLongwave (LW) radiation, in the context of climate science, is electromagnetic thermal radiation emitted by Earth's surface, atmosphere, and clouds. Longwave radiation may also be referred to as terrestrial radiation, thermal infrared radiation, or thermal radiation. This radiation is in the infrared portion of the spectrum, but is distinct from (i.e., has a longer wavelength than) the shortwave (SW) near-infrared radiation found in sunlight. Outgoing longwave radiation (OLR) is the longwave radiation emitted to space from the top of Earth's atmosphere.
Altitudinal zonationAltitudinal zonation (or elevational zonation) in mountainous regions describes the natural layering of ecosystems that occurs at distinct elevations due to varying environmental conditions. Temperature, humidity, soil composition, and solar radiation are important factors in determining altitudinal zones, which consequently support different vegetation and animal species. Altitudinal zonation was first hypothesized by geographer Alexander von Humboldt who noticed that temperature drops with increasing elevation.
