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Foehn
A Foehn, or Föhn (, , , ), is a type of dry, relatively warm downslope wind in the lee of a mountain range. It is a rain shadow wind that results from the subsequent adiabatic warming of air that has dropped most of its moisture on windward slopes (see orographic lift). As a consequence of the different adiabatic lapse rates of moist and dry air, the air on the leeward slopes becomes warmer than equivalent elevations on the windward slopes. Foehn winds can raise temperatures by as much as in just a matter of hours. Switzerland, southern Germany, and Austria have a warmer climate due to the Foehn, as moist winds off the Mediterranean Sea blow over the Alps. Etymology The name ''Foehn'' (, ) arose in the Alpine region. Originating from Latin , a mild west wind of which Favonius was the Roman personification and probably transmitted by or just , the term was adopted as . In the Southern Alps, the phenomenon is known as but also and in Serbo-Croatian and Slovene. The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Foehn Effect Mechanisms
A Foehn, or Föhn (, , , ), is a type of dry, relatively warm katabatic wind, downslope wind in the leeward, lee of a mountain range. It is a rain shadow wind that results from the subsequent adiabatic warming of air that has dropped most of its moisture on windward and leeward, windward slopes (see orographic lift). As a consequence of the different adiabatic lapse rates of moist and dry air, the air on the leeward slopes becomes warmer than equivalent elevations on the windward slopes. Foehn winds can raise atmospheric temperature, temperatures by as much as in just a matter of hours. Switzerland, southern Germany, and Austria have a warmer climate due to the Foehn, as moist winds off the Mediterranean Sea blow over the Alps. Etymology The name ''Foehn'' (, ) arose in the Alps, Alpine region. Originating from Latin , a mild west wind of which Zephyrus, Favonius was the Roman personification and probably transmitted by or just , the term was adopted as . In the Southern A ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Foehn Rotor Cloud
A Foehn, or Föhn (, , , ), is a type of dry, relatively warm downslope wind in the lee of a mountain range. It is a rain shadow wind that results from the subsequent adiabatic warming of air that has dropped most of its moisture on windward slopes (see orographic lift). As a consequence of the different adiabatic lapse rates of moist and dry air, the air on the leeward slopes becomes warmer than equivalent elevations on the windward slopes. Foehn winds can raise temperatures by as much as in just a matter of hours. Switzerland, southern Germany, and Austria have a warmer climate due to the Foehn, as moist winds off the Mediterranean Sea blow over the Alps. Etymology The name ''Foehn'' (, ) arose in the Alpine region. Originating from Latin , a mild west wind of which Favonius was the Roman personification and probably transmitted by or just , the term was adopted as . In the Southern Alps, the phenomenon is known as but also and in Serbo-Croatian and Slovene. T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Katabatic Wind
A katabatic wind (named ) is a downslope wind caused by the flow of an elevated, high-density air mass into a lower-density air mass below under the force of gravity. The spelling catabatic is also used. Since air density is strongly dependent on temperature, the high-density air mass is usually cooler, and the katabatic winds are relatively cool or cold. Examples of katabatic winds include the downslope valley and mountain breezes, the piteraq winds of Greenland, the Bora in the Adriatic, the Bohemian Wind or ''Böhmwind'' in the Ore Mountains, the Santa Ana winds in southern California, the oroshi in Japan, or "the Barber" in New Zealand. Not all downslope winds are katabatic. For instance, winds such as the föhn and chinook are rain shadow winds where air driven upslope on the windward side of a mountain range drops its moisture and descends leeward drier and warmer. Mechanism A katabatic wind originates from the difference of density of two air masses located ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Windward And Leeward
In geography and seamanship, windward () and leeward () are directions relative to the wind. Windward is ''upwind'' from the point of reference, i.e., towards the direction from which the wind is coming; leeward is ''downwind'' from the point of reference, i.e., along the direction towards which the wind is going. The side of a ship that is towards the leeward is its "lee side". If the vessel is heeling under the pressure of crosswind, the lee side will be the "lower side". During the Age of Sail, the term ''weather'' was used as a synonym for ''windward'' in some contexts, as in the '' weather gage''. Since it captures rainfall, the windward side of a mountain tends to be wetter than the leeward side it blocks. The drier leeward area is said to be in a rain shadow. Origin The term "windward" has roots in both Low German and Old English. The word "lee", which means a place without wind, comes from the Old Norse "hle" for "cover" and has been used in marine navigation in G ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alpine Föhn
The Alpine föhn () is the name given to the föhn wind in the Alps, Alpine region. The name ''föhn'' was originally used to refer to the south wind which blows during the winter months and brings thaw conditions to the northern side of the Alps. Because föhn later became a generic term that was extended to other mountain ranges around the world that experience similar phenomena, the name "Alpine föhn" (''Alpenföhn'') was coined for the föhns of the Alpine region.''Der Brockhaus. Wetter und Klima.'' Seite 101, Brockhaus, Leipzig/Mannheim, 2009, The wind can cause heavy storms with winds of hurricane strength and top speeds of up to . The south wind on the northern side of the Alps is also called the south föhn (''Südföhn''), its opposite number on the south side of the Alps is also called the north föhn (''Nordföhn''). Föhn conditions are known for their warm air and unusual cloud and atmospheric appearance. Föhns in the north Alps A considerable proportion of fö ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lapse Rate
The lapse rate is the rate at which an atmospheric variable, normally temperature in Earth's atmosphere, falls with altitude. ''Lapse rate'' arises from the word ''lapse'' (in its "becoming less" sense, not its "interruption" sense). In dry air, the adiabatic lapse rate (i.e., decrease in temperature of a parcel of air that rises in the atmosphere without exchanging energy with surrounding air) is 9.8 °C/km (5.4 °F per 1,000 ft). The saturated adiabatic lapse rate (SALR), or moist adiabatic lapse rate (MALR), is the decrease in temperature of a parcel of water-saturated air that rises in the atmosphere. It varies with the temperature and pressure of the parcel and is often in the range 3.6 to (2 to ), as obtained from the International Civil Aviation Organization (ICAO). The environmental lapse rate is the decrease in temperature of air with altitude for a specific time and place (see below). It can be highly variable between circumstances. Lapse rate corresponds to the vertic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Leeward
In geography and seamanship, windward () and leeward () are directions relative to the wind. Windward is ''upwind'' from the point of reference, i.e., towards the direction from which the wind is coming; leeward is ''downwind'' from the point of reference, i.e., along the direction towards which the wind is going. The side of a ship that is towards the leeward is its "lee side". If the vessel is heeling under the pressure of crosswind, the lee side will be the "lower side". During the Age of Sail, the term ''weather'' was used as a synonym for ''windward'' in some contexts, as in the '' weather gage''. Since it captures rainfall, the windward side of a mountain tends to be wetter than the leeward side it blocks. The drier leeward area is said to be in a rain shadow. Origin The term "windward" has roots in both Low German and Old English. The word "lee", which means a place without wind, comes from the Old Norse "hle" for "cover" and has been used in marine navigation in G ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rain Shadow
A rain shadow is an area of significantly reduced rainfall behind a mountainous region, on the side facing away from prevailing winds, known as its leeward side. Evaporated moisture from body of water, bodies of water (such as oceans and large lakes) is carried by the prevailing sea breeze, onshore breezes towards the drier and hotter inland areas. When encountering elevated landforms, the moist air is orographic lift, driven upslope towards the summit, peak, where it expands, cools, and its moisture condenses and starts to Precipitation, precipitate. If the landforms are tall and wide enough, most of the humidity will be lost to precipitation over the windward side (also known as the ''rainward'' side) before ever making it past the top. As the air descends the leeward side of the landforms, it is compressed and heated, producing Foehn winds that ''absorb'' moisture downslope and cast a broad "shadow" of arid, dry climate region behind the ridge, mountain crests. This climate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eiger
The Eiger () is a mountain of the Bernese Alps, overlooking Grindelwald and Lauterbrunnen in the Bernese Oberland of Switzerland, just north of the main watershed and border with Valais. It is the easternmost peak of a ridge crest that extends across the Mönch to the Jungfrau at , constituting one of the most emblematic sights of the Swiss Alps. While the northern side of the mountain rises more than 3,000 m (10,000 ft) above the two valleys of Grindelwald and Lauterbrunnen, the southern side faces the large glaciers of the Jungfrau-Aletsch area, the most glaciated region in the Alps. The most notable feature of the Eiger is its nearly north face of rock and ice, named ''Eiger-Nordwand'', ''Eigerwand'' or just ''Nordwand'', which is the biggest north face in the Alps. This substantial face towers over the resort of Kleine Scheidegg at its base, on the eponymous pass connecting the two valleys. The first ascent of the Eiger was made by Swiss guides Christian Alm ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Humidity
Humidity is the concentration of water vapor present in the air. Water vapor, the gaseous state of water, is generally invisible to the human eye. Humidity indicates the likelihood for precipitation (meteorology), precipitation, dew, or fog to be present. Humidity depends on the temperature and pressure of the system of interest. The same amount of water vapor results in higher relative humidity in cool air than warm air. A related parameter is the dew point. The amount of water vapor needed to achieve saturation increases as the temperature increases. As the temperature of a parcel of air decreases it will eventually reach the saturation point without adding or losing water mass. The amount of water vapor contained within a parcel of air can vary significantly. For example, a parcel of air near saturation may contain 8 g of water per cubic metre of air at , and 28 g of water per cubic metre of air at Three primary measurements of humidity are widely employed: abso ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Genericized Trademark
A generic trademark, also known as a genericized trademark or proprietary eponym, is a trademark or brand name that, because of its popularity or significance, has become the generic term for, or synonymous with, a general class of products or services, usually against the intentions of the trademark's owner. A trademark is prone to genericization, or "genericide", when a brand name acquires substantial market dominance or mind share, becoming so widely used for similar products or services that it is no longer associated with the trademark owner, e.g., linoleum, bubble wrap, thermos, and aspirin. A trademark thus popularized is at risk of being challenged or revoked, unless the trademark owner works sufficiently to correct and prevent such broad use. Trademark owners can inadvertently contribute to genericization by failing to provide an alternative generic name for their product or service or using the trademark in similar fashion to generic terms. In one example, the Oti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sublimation (chemistry)
Sublimation is the Phase transition, transition of a substance directly from the solid to the gas state, without passing through the liquid state. The verb form of sublimation is ''sublime'', or less preferably, ''sublimate''. ''Sublimate'' also refers to the product obtained by sublimation. The point at which sublimation occurs rapidly (for further details, see #False correspondence with vaporization, below) is called critical sublimation point, or simply sublimation point. Notable examples include sublimation of dry ice at room temperature and atmospheric pressure, and that of solid iodine with heating. The reverse process of sublimation is deposition (phase transition), ''deposition'' (also called ''desublimation''), in which a substance passes directly from a gas to a solid phase, without passing through the liquid state. Technically, all solids may sublime, though most sublime at extremely low rates that are hardly detectable under usual conditions. At standard condi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
