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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] |
Mountain Breeze And Valley Breeze
In meteorology, a mountain breeze and a valley breeze are two related, localized winds that occur one after the other on a daily cycle. They are an example of anabatic and katabatic winds occurring at local scales. These winds are opposite from each other. Mountain winds blow from mountain towards valley after sunset, when mountain cools down and valley zone is comparatively warmer. While valley breezes occur when the warm air rises up the sides of the valley, warm air in a mountain breeze will rise up the middle. Cause Mountain and valley breezes form through a process similar to sea and land breezes. During the day, the sun heats up mountain air rapidly while the valley remains relatively cooler. Convection Convection is single or Multiphase flow, multiphase fluid flow that occurs Spontaneous process, spontaneously through the combined effects of material property heterogeneity and body forces on a fluid, most commonly density and gravity (see buoy ... causes it to rise, ... [...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] |
Tierra Del Fuego
Tierra del Fuego (, ; Spanish for "Land of Fire", rarely also Fireland in English) is an archipelago off the southernmost tip of the South America, South American mainland, across the Strait of Magellan. The archipelago consists of the main island, Isla Grande de Tierra del Fuego, with an area of , along with numerous smaller islands, including Cape Horn and Diego Ramírez Islands. The western part of the Tierra del Fuego archipelago, about two-thirds including its many islands, is part of Chile, and the eastern part is part of Argentina. The southernmost extent of the archipelago, Cape Horn, lies just north of latitude 56th parallel south, 56°S. The earliest-known human settlement in Tierra del Fuego dates to approximately 8,000 BC. Europeans first explored the islands during Ferdinand Magellan's expedition of 1520. ''Tierra del Fuego'' ("Land of Fire") and similar names stem from sightings of the many fires that the inhabitants built along the coastline and possibly even in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sublimation (phase Transition)
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] |
Blue-ice Area
A blue-ice area is an ice-covered area of Antarctica where wind-driven snow transport and sublimation result in net mass loss from the ice surface in the absence of melting, forming a blue surface that contrasts with the more common white Antarctic surface. Such blue-ice areas typically form when the movement of both air and ice are obstructed by topographic obstacles such as mountains that emerge from the ice sheet, generating particular climatic conditions where the net snow accumulation is exceeded by wind-driven sublimation and snow transports. Only about 1% of Antarctic ice area can be considered to be blue-ice area, but they have attracted scientific interest due to the large numbers of meteorites that accumulate on them; these meteorites either fall directly on the blue-ice area and remain there, or they fall elsewhere into the ice sheet and are transported to the blue-ice area by ice flow. Additionally, ice up to 2.7 million years old has been obtained from blue-i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Desiccation
Desiccation is the state of extreme dryness, or the process of extreme drying. A desiccant is a hygroscopic (attracts and holds water) substance that induces or sustains such a state in its local vicinity in a moderately sealed container. The word desiccation comes . Industry Desiccation is widely employed in the oil and gas industry. These materials are obtained in a hydrated state, but the water content leads to corrosion or is incompatible with downstream processing. Removal of water is achieved by cryogenics, cryogenic condensation, absorption into glycols, and absorption onto desiccants such as silica gel. Laboratory A desiccator is a heavy glass or plastic container, now somewhat antiquated, used in practical chemistry for drying or keeping small amounts of materials very dry. The material is placed on a shelf, and a drying agent or ''desiccant'', such as dry silica gel or anhydrous sodium hydroxide, is placed below the shelf. Often some sort of humidity indicator is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
McMurdo Dry Valleys
The McMurdo Dry Valleys are a row of largely Antarctic oasis, snow-free valleys in Antarctica, located within Victoria Land west of McMurdo Sound. The Dry Valleys experience extremely low humidity and surrounding mountains prevent the flow of ice from nearby glaciers. The rocks there are granites and gneisses, and glacial tills dot this bedrock landscape, with loose gravel covering the ground. It is one of the driest places on Earth, though there are several anecdotal accounts of rainfall within the Dry Valleys. The region is one of the world's most extreme deserts, and includes many features including Lake Vida, a saline lake, and the Onyx River, a meltwater stream and Antarctica's longest river. Although no living organisms have been found in the permafrost here, Endolithic lichen, endolithic Photosynthesis, photosynthetic bacteria have been found living in the relatively moist interior of rocks, and anaerobic bacteria, with a metabolism based on iron and sulfur, live under ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Antarctic Oasis
An Antarctic oasis is a large area naturally free of snow and ice in the otherwise ice-covered continent of Antarctica. Geology In Antarctica there are, in addition to mountaintops and nunataks, other natural snow- and ice-free areas often referred to as "Antarctic oases" or "dry valleys". These areas are surrounded by the Antarctic ice sheet or, in coastal areas, are situated between the ice sheet and the Antarctic ice shelves. Antarctic oases and dry valleys develop in areas with particular regional weather patterns and geography. These areas have very low humidity and precipitation. Although these areas are very cold, sufficient solar energy is absorbed by the ground to melt what little snow does fall, or else it is scoured or sublimated by katabatic winds, leaving the underlying rock exposed. Despite usually extreme aridity, some plants, in the form of bryophytes and lichens, can survive in Antarctic oases. Geography The larger oases (with their respective areas) ar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Greenland
Greenland is an autonomous territory in the Danish Realm, Kingdom of Denmark. It is by far the largest geographically of three constituent parts of the kingdom; the other two are metropolitan Denmark and the Faroe Islands. Citizens of Greenland are full Danish nationality law, citizens of Denmark and European Union citizenship, of the European Union. Greenland is one of the Special territories of members of the European Economic Area#Overseas countries and territories, Overseas Countries and Territories of the European Union and is part of the Council of Europe. It is the List of islands by area, world's largest island, and lies between the Arctic Ocean, Arctic and Atlantic oceans, east of the Arctic Archipelago, Canadian Arctic Archipelago. It is the location of the northernmost point of land in the world; Kaffeklubben Island off the northern coast is the world's Northernmost point of land, northernmost undisputed point of land—Cape Morris Jesup on the mainland was thought to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Antarctica
Antarctica () is Earth's southernmost and least-populated continent. Situated almost entirely south of the Antarctic Circle and surrounded by the Southern Ocean (also known as the Antarctic Ocean), it contains the geographic South Pole. Antarctica is the fifth-largest continent, being about 40% larger than Europe, and has an area of . Most of Antarctica is covered by the Antarctic ice sheet, with an average thickness of . Antarctica is, on average, the coldest, driest, and windiest of the continents, and it has the highest average elevation. It is mainly a polar desert, with annual Climate of Antarctica#Precipitation, precipitation of over along the coast and far less inland. About 70% of the world's freshwater reserves are frozen in Antarctica, which, if melted, would raise global sea levels by almost . Antarctica holds the record for the Lowest temperature recorded on Earth, lowest measured temperature on Earth, . The coastal regions can reach temperatures over in the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sea Ice By Fruchtzwerg's World
A sea is a large body of salt water. There are particular seas and the sea. The sea commonly refers to the ocean, the interconnected body of seawaters that spans most of Earth. Particular seas are either marginal seas, second-order sections of the oceanic sea (e.g. the Mediterranean Sea), or certain large, nearly landlocked bodies of water. The salinity of water bodies varies widely, being lower near the surface and the mouths of large rivers and higher in the depths of the ocean; however, the relative proportions of dissolved salts vary little across the oceans. The most abundant solid dissolved in seawater is sodium chloride. The water also contains salts of magnesium, calcium, potassium, and mercury, among other elements, some in minute concentrations. A wide variety of organisms, including bacteria, protists, algae, plants, fungi, and animals live in various marine habitats and ecosystems throughout the seas. These range vertically from the sunlit surface and shorelin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
