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Thermal Bar
A thermal bar is a hydrodynamic feature that forms around the edges of holomictic lakes during the seasonal transition to stratified conditions, due to the shorter amount of time required for shallow areas of the lake to stratify. Description During the process of lake stratification, shallow areas generally become stratified before deeper areas. In large lakes this condition may persist for weeks, during which a temperature front known as a thermal bar forms between the stratified and unstratified areas of the lake. The thermal bar generally forms parallel to shore and moves toward the lake center as deeper areas of the lake stratify. While thermal bars can form in both fall and spring, most studies of the thermal bar have investigated aspects of the feature in the spring, when the lake is warming up and the summer thermocline is beginning to form. At the lake surface, the thermal bar may be visible as a foam line between the stratified water shoreward of the thermal bar and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydrodynamic
In physics and engineering, fluid dynamics is a subdiscipline of fluid mechanics that describes the flow of fluids—liquids and gases. It has several subdisciplines, including ''aerodynamics'' (the study of air and other gases in motion) and hydrodynamics (the study of liquids in motion). Fluid dynamics has a wide range of applications, including calculating forces and moments on aircraft, determining the mass flow rate of petroleum through pipelines, predicting weather patterns, understanding nebulae in interstellar space and modelling fission weapon detonation. Fluid dynamics offers a systematic structure—which underlies these practical disciplines—that embraces empirical and semi-empirical laws derived from flow measurement and used to solve practical problems. The solution to a fluid dynamics problem typically involves the calculation of various properties of the fluid, such as flow velocity, pressure, density, and temperature, as functions of space and time. Be ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cyclonic
In meteorology, a cyclone () is a large air mass that rotates around a strong center of low atmospheric pressure, counterclockwise in the Northern Hemisphere and clockwise in the Southern Hemisphere as viewed from above (opposite to an anticyclone). Cyclones are characterized by inward-spiraling winds that rotate about a zone of low pressure. The largest low-pressure systems are polar vortices and extratropical cyclones of the largest scale (the synoptic scale). Warm-core cyclones such as tropical cyclones and subtropical cyclones also lie within the synoptic scale. Mesocyclones, tornadoes, and dust devils lie within smaller mesoscale. Upper level cyclones can exist without the presence of a surface low, and can pinch off from the base of the tropical upper tropospheric trough during the summer months in the Northern Hemisphere. Cyclones have also been seen on extraterrestrial planets, such as Mars, Jupiter, and Neptune. Cyclogenesis is the process of cyclone formation a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Water
Water (chemical formula ) is an inorganic, transparent, tasteless, odorless, and nearly colorless chemical substance, which is the main constituent of Earth's hydrosphere and the fluids of all known living organisms (in which it acts as a solvent). It is vital for all known forms of life, despite not providing food, energy or organic micronutrients. Its chemical formula, H2O, indicates that each of its molecules contains one oxygen and two hydrogen atoms, connected by covalent bonds. The hydrogen atoms are attached to the oxygen atom at an angle of 104.45°. "Water" is also the name of the liquid state of H2O at standard temperature and pressure. A number of natural states of water exist. It forms precipitation in the form of rain and aerosols in the form of fog. Clouds consist of suspended droplets of water and ice, its solid state. When finely divided, crystalline ice may precipitate in the form of snow. The gaseous state of water is steam or water vapor. W ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Limnology
Limnology ( ; from Greek λίμνη, ''limne'', "lake" and λόγος, ''logos'', "knowledge") is the study of inland aquatic ecosystems. The study of limnology includes aspects of the biological, chemical, physical, and geological characteristics of fresh and saline, natural and man-made bodies of water. This includes the study of lakes, reservoirs, ponds, rivers, springs, streams, wetlands, and groundwater.Wetzel, R.G. 2001. Limnology: Lake and River Ecosystems, 3rd ed. Academic Press () Water systems are often categorized as either running (lotic) or standing (lentic). Limnology includes the study of the drainage basin, movement of water through the basin and biogeochemical changes that occur en route. A more recent sub-discipline of limnology, termed landscape limnology, studies, manages, and seeks to conserve these ecosystems using a landscape perspective, by explicitly examining connections between an aquatic ecosystem and its drainage basin. Recently, the need to un ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Water (molecule)
Water () is a polar inorganic compound that is at room temperature a tasteless and odorless liquid, which is nearly colorless apart from an inherent hint of blue. It is by far the most studied chemical compound and is described as the "universal solvent" and the "solvent of life". It is the most abundant substance on the surface of Earth and the only common substance to exist as a solid, liquid, and gas on Earth's surface. It is also the third most abundant molecule in the universe (behind molecular hydrogen and carbon monoxide). Water molecules form hydrogen bonds with each other and are strongly polar. This polarity allows it to dissociate ions in salts and bond to other polar substances such as alcohols and acids, thus dissolving them. Its hydrogen bonding causes its many unique properties, such as having a solid form less dense than its liquid form, a relatively high boiling point of 100 °C for its molar mass, and a high heat capacity. Water is amphoteric, me ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lake Ecosystem
A lake ecosystem or lacustrine ecosystem includes biotic (living) plants, animals and micro-organisms, as well as abiotic (non-living) physical and chemical interactions. Lake ecosystems are a prime example of lentic ecosystems (''lentic'' refers to stationary or relatively still freshwater, from the Latin ''lentus'', which means "sluggish"), which include ponds, lakes and wetlands, and much of this article applies to lentic ecosystems in general. Lentic ecosystems can be compared with lotic ecosystems, which involve flowing terrestrial waters such as rivers and streams. Together, these two ecosystems are examples of freshwater ecosystems. Lentic systems are diverse, ranging from a small, temporary rainwater pool a few inches deep to Lake Baikal, which has a maximum depth of 1642 m. The general distinction between pools/ponds and lakes is vague, but Brown states that ponds and pools have their entire bottom surfaces exposed to light, while lakes do not. In addition, some lakes ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Laurentian Great Lakes
The Great Lakes, also called the Great Lakes of North America, are a series of large interconnected freshwater lakes in the mid-east region of North America that connect to the Atlantic Ocean via the Saint Lawrence River. There are five lakes, which are Superior, Michigan, Huron, Erie, and Ontario and are in general on or near the Canada–United States border. Hydrologically, lakes Michigan and Huron are a single body joined at the Straits of Mackinac. The Great Lakes Waterway enables modern travel and shipping by water among the lakes. The Great Lakes are the largest group of freshwater lakes on Earth by total area and are second-largest by total volume, containing 21% of the world's surface fresh water by volume. The total surface is , and the total volume (measured at the low water datum) is , slightly less than the volume of Lake Baikal (, 22–23% of the world's surface fresh water). Because of their sea-like characteristics, such as rolling waves, sustained winds, st ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lake Baikal
Lake Baikal (, russian: Oзеро Байкал, Ozero Baykal ); mn, Байгал нуур, Baigal nuur) is a rift lake in Russia. It is situated in southern Siberia, between the Federal subjects of Russia, federal subjects of Irkutsk Oblast, Irkutsk Oblasts of Russia, Oblast to the northwest and the Republic of Buryatia to the southeast. With of water, Lake Baikal is the world's List of lakes by volume, largest freshwater lake by volume, containing 22–23% of the world's fresh surface water, more than all of the North American Great Lakes combined. It is also the world's List of lakes by depth, deepest lake, with a maximum depth of , and the world's ancient lake, oldest lake, at 25–30 million years. At —slightly larger than Belgium—Lake Baikal is the world's List of lakes by area, seventh-largest lake by surface area. It is among the world's clearest lakes. Lake Baikal is home to thousands of species of Plant, plants and animals, many of them endemic to the region. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lake Ladoga
Lake Ladoga (; rus, Ла́дожское о́зеро, r=Ladozhskoye ozero, p=ˈladəʂskəjə ˈozʲɪrə or rus, Ла́дога, r=Ladoga, p=ˈladəɡə, fi, Laatokka arlier in Finnish ''Nevajärvi'' ; vep, Ladog, Ladoganjärv) is a freshwater lake located in the Republic of Karelia and Leningrad Oblast in northwestern Russia, in the vicinity of Saint Petersburg. It is the largest lake located entirely in Europe, the second largest lake after Baikal in Russia, and the 14th largest freshwater lake by area in the world. '' Ladoga Lacus'', a methane lake on Saturn's moon Titan, is named after the lake. Etymology In one of Nestor's chronicles from the 12th century a lake called "the Great Nevo" is mentioned, a clear link to the Neva River and possibly further to Finnish ''nevo'' 'sea' or ''neva'' 'bog, quagmire'. Evgeny Pospelov: ''Geographical names of the world. Toponymic dictionary.'' Second edition. Astrel, Moscow 2001, pp. 106f. Ancient Norse sagas and Hanseatic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lac Leman
, image = Lake Geneva by Sentinel-2.jpg , caption = Satellite image , image_bathymetry = , caption_bathymetry = , location = Switzerland, France , coords = , lake_type = Glacial lake , inflow = Rhône, Dranse , outflow = Rhône , catchment = , basin_countries = Switzerland, France , length = , width = , area = , depth = , max-depth = , volume = , residence_time = 11.4 years , shore = , elevation = , islands = Île de Peilz, Château de Chillon, Île de Salagnon, Île de la Harpe, Île Rousseau, Île de Choisi , cities = Geneva (CH), Lausanne (CH), Évian (F), Montreux (CH), Thonon (F), Vevey (CH) (''see list'') , pushpin_map=France Rhône-Alpes#Canton of Vaud#Canton of Valais#Switzerland#France#Alps , pushpin_label_position= bottom , e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
François-Alphonse Forel
François-Alphonse Forel (February 2, 1841 – August 7, 1912) was a Swiss physician and scientist who pioneered the study of lakes, and is thus considered the founder, and the Father of limnology.Prof. F. A. Forel. Nature 89, 638–639 (1912). https://doi.org/10.1038/089638b0 Limnology is the study of bodies of fresh water and their biological, chemical, and physical features. Childhood and Family Forel was born in Morges, Switzerland on Lake Geneva. His father, François Marie Etienne Forel (1765-1865) was a well-respected historian and a jurist and was a strong influence in Forel's life. From a young age, François-Alphonse Forel became involved in some of archaeological studies of his father's colleagues. Several of Forel's family members were also respected scholars and scientists. Education Forel began his education at the Collège de Morges. Eventually, he left Morges for secondary school in Geneva at the Gymnase de Genève. There, he studied the natural sciences and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geostrophic Current
A geostrophic current is an oceanic current in which the pressure gradient force is balanced by the Coriolis effect. The direction of geostrophic flow is parallel to the isobars, with the high pressure to the right of the flow in the Northern Hemisphere, and the high pressure to the left in the Southern Hemisphere. This concept is familiar from weather maps, whose isobars show the direction of geostrophic winds. Geostrophic flow may be either barotropic or baroclinic. A geostrophic current may also be thought of as a rotating shallow water wave with a frequency of zero. The principle of ''geostrophy'' or ''geostrophic balance'' is useful to oceanographers because it allows them to infer ocean currents from measurements of the sea surface height (by combined satellite altimetry and gravimetry) or from vertical profiles of seawater density taken by ships or autonomous buoys. The major currents of the world's oceans, such as the Gulf Stream, the Kuroshio Current, the Agulhas C ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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