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Wind Speed
In meteorology, wind speed, or wind flow speed, is a fundamental atmospheric quantity caused by air moving from high to low pressure, usually due to changes in temperature. Wind speed is now commonly measured with an anemometer. Wind speed affects weather forecasting, aviation and maritime operations, construction projects, growth and metabolism rates of many plant species, and has countless other implications. Wind direction is usually almost parallel to isobars (and not perpendicular, as one might expect), due to Earth's rotation. Units The meter per second (m/s) is the SI unit for velocity and the unit recommended by the World Meteorological Organization for reporting wind speeds, and used amongst others in weather forecasts in the Nordic countries. Since 2010 the International Civil Aviation Organization (ICAO) also recommends meters per second for reporting wind speed when approaching runways, replacing their former recommendation of using kilometers per hour ( ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Weather Station At Feilding Waste Water Treatment Plant
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 cloudy. On Earth, most weather phenomena occur in the lowest layer of the planet's atmosphere, the troposphere, just below the stratosphere. Weather refers to day-to-day temperature, precipitation, and other atmospheric conditions, whereas climate is the term for the averaging of atmospheric conditions over longer periods of time. When used without qualification, "weather" is generally understood to mean the weather of Earth. Weather is driven by air pressure, temperature, and moisture differences between one place and another. These differences can occur due to the Sun's angle at any particular spot, which varies with latitude. The strong temperature contrast between polar and tropical air gives rise to the largest scale atmospheric circulations: the Hadley cell, the Ferrel cell, the polar cell, and the jet stream. Weather systems in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Earth's Rotation
Earth's rotation or Earth's spin is the rotation of planet Earth around its own Rotation around a fixed axis, axis, as well as changes in the orientation (geometry), orientation of the rotation axis in space. Earth rotates eastward, in prograde motion. As viewed from the northern polar star Polaris, Earth turns counterclockwise. The North Pole, also known as the Geographic North Pole or Terrestrial North Pole, is the point in the Northern Hemisphere where Earth's axis of rotation meets its surface. This point is distinct from Earth's north magnetic pole. The South Pole is the other point where Earth's axis of rotation intersects its surface, in Antarctica. Earth rotates once in about 24 hours with respect to the Sun, but once every 23 hours, 56 minutes and 4 seconds with respect to other distant stars (#Stellar and sidereal day, see below). Earth's rotation is slowing slightly with time; thus, a day was shorter in the past. This is due to the tidal acceleration, tidal effects ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rossby Wave
Rossby waves, also known as planetary waves, are a type of inertial wave naturally occurring in rotating fluids. They were first identified by Sweden-born American meteorologist Carl-Gustaf Arvid Rossby in the Earth's atmosphere in 1939. They are observed in the atmospheres and oceans of Earth and other planets, owing to the rotation of Earth or of the planet involved. Atmospheric Rossby waves on Earth are giant meanders in high-altitude winds that have a major influence on weather. These waves are associated with pressure systems and the jet stream (especially around the polar vortices). Oceanic Rossby waves move along the thermocline: the boundary between the warm upper layer and the cold deeper part of the ocean. Rossby wave types Atmospheric waves Atmospheric Rossby waves result from the conservation of potential vorticity and are influenced by the Coriolis force and pressure gradient. The image on the left sketches fundamental principles of the wave, e.g., its restorin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pressure Gradient
In hydrodynamics and hydrostatics, the pressure gradient (typically of air but more generally of any fluid) is a physical quantity that describes in which direction and at what rate the pressure increases the most rapidly around a particular location. The pressure gradient is a dimensional quantity expressed in units of pascals per metre (Pa/m). Mathematically, it is the gradient of pressure as a function of position. The gradient of pressure in hydrostatics is equal to the ''body force density'' (generalised Stevin's Law). In petroleum geology and the petrochemical sciences pertaining to oil wells, and more specifically within hydrostatics, pressure gradients refer to the gradient of vertical pressure in a column of fluid within a wellbore and are generally expressed in pounds per square inch per foot (psi/ft). This column of fluid is subject to the compound pressure gradient of the overlying fluids. The path and geometry of the column is totally irrelevant; only the vertical ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Beaufort Scale
The Beaufort scale ( ) is an empirical measure that relates wind speed to observed conditions at sea or on land. Its full name is the Beaufort wind force scale. It was devised in 1805 by Francis Beaufort a hydrographer in the Royal Navy. It was officially adopted by the Royal Navy and later spread internationally. History The scale that carries Beaufort's name had a long and complex evolution from the previous work of others (including Daniel Defoe the century before). In the 18th century, naval officers made regular weather observations, but there was no standard scale and so they could be very subjective — one man's "stiff breeze" might be another's "soft breeze"—: Beaufort succeeded in standardising a scale.reprinted in 2003 by Dover Publications./ref> The scale was devised in 1805 by Francis Beaufort (later Rear Admiral), a hydrographer and a Royal Navy officer, while serving on , and refined until he was Hydrographer of the Navy in the 1830s, when it was ado ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Feet Per Second
The foot per second (plural feet per second) is a unit of both speed (scalar) and velocity (vector quantity, which includes direction). It expresses the distance in feet (ft) traveled or displaced, divided by the time in seconds (s). The corresponding unit in the International System of Units The International System of Units, internationally known by the abbreviation SI (from French ), is the modern form of the metric system and the world's most widely used system of measurement. It is the only system of measurement with official s ... (SI) is the meter per second. Abbreviations include ft/s, fps, and the scientific notation ft s−1. Conversions See also * Foot per second squared, a corresponding unit of acceleration. * Feet per minute References Units of velocity Customary units of measurement in the United States {{physics-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Knot (unit)
The knot () is a unit of speed equal to one nautical mile per hour, exactly (approximately or ). The ISO standard symbol for the knot is kn. The same symbol is preferred by the Institute of Electrical and Electronics Engineers ( IEEE), while kt is also common, especially in aviation, where it is the form recommended by the International Civil Aviation Organization ( ICAO). The knot is a non- SI unit. The knot is used in meteorology, and in maritime and air navigation. A vessel travelling at 1 knot along a meridian travels approximately one minute of geographic latitude in one hour. Definitions ;1 international knot = :1 nautical mile per hour (by definition), : (exactly), : (approximately), : (approximately), : (approximately) : (approximately). The length of the internationally agreed nautical mile is . The US adopted the international definition in 1954, having previously used the US nautical mile (). The UK adopted the international nautical mile defi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Miles Per Hour
Miles per hour (mph, m.p.h., MPH, or mi/h) is a British imperial and United States customary unit of speed expressing the number of miles travelled in one hour. It is used in the United Kingdom, the United States, and a number of smaller countries, most of which are UK or US territories, or have close historical ties with the UK or US. Usage Road traffic Speed limits and road traffic speeds are given in miles per hour in the following jurisdictions: *Antigua and Barbuda *Bahamas *Belize *Dominica *Grenada *Liberia (occasionally) *Marshall Islands * Micronesia *Palau *Saint Kitts and Nevis *Saint Lucia * Saint Vincent and the Grenadines *United Kingdom *The following British Overseas Territories: **Anguilla **British Virgin Islands ** British Indian Ocean Territory **Cayman Islands **Falkland Islands **Montserrat **Saint Helena, Ascension and Tristan da Cunha **Turks and Caicos Islands *The Crown dependencies: **Bailiwick of Guernsey **Isle of Man **Jersey *United St ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kilometres Per Hour
The kilometre per hour (International System of Units, SI symbol: km/h; non-SI abbreviations: kph, kmph, km/hr) is a Units of measurement, unit of speed, expressing the number of kilometres travelled in one hour. History Although the metre was formally defined in 1799, the term "kilometres per hour" did not come into immediate use – the myriametre () and myriametre per hour were preferred to kilometres and kilometres per hour. In 1802 the term "''myriamètres par heure''" appeared in French literature. The Dutch on the other hand adopted the kilometre in 1817 but gave it the local name of the ''mijl'' (Mile#Other historical miles, Dutch mile). Notation history The SI representations, classified as symbols, are "km/h", "" and "". Several other abbreviations of "kilometres per hour" have been used since the term was introduced and many are still in use today; for example, dictionaries list "kph", [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Runway
In aviation, a runway is an elongated, rectangular surface designed for the landing and takeoff of an aircraft. Runways may be a human-made surface (often asphalt concrete, asphalt, concrete, or a mixture of both) or a natural surface (sod, grass, soil, dirt, gravel, ice, sand or road salt, salt). Runways, taxiways and Airport apron, ramps, are sometimes referred to as "tarmac", though very few runways are built using Tarmacadam, tarmac. Takeoff and landing areas defined on the surface of water for seaplanes are generally referred to as waterways. Runway lengths are now International Civil Aviation Organization#Use of the International System of Units, commonly given in meters worldwide, except in North America where feet are commonly used. History In 1916, in a World War I war effort context, the first concrete-paved runway was built in Clermont-Ferrand in France, allowing local company Michelin to manufacture Bréguet Aviation military aircraft. In January 1919, aviation p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
International Civil Aviation Organization
The International Civil Aviation Organization (ICAO ) is a specialized agency of the United Nations that coordinates the principles and techniques of international air navigation, and fosters the planning and development of international scheduled air transport, air transport to ensure safe and orderly growth. The ICAO headquarters are located in the Quartier international de Montréal of Montreal, Quebec, Canada. The ICAO Council adopts standards and recommended practices concerning air navigation, its infrastructure, flight inspection, prevention of unlawful interference, and facilitation of border-crossing procedures for international civil aviation. ICAO defines the protocols for Aviation accidents and incidents, air accident investigation that are followed by :Organizations investigating aviation accidents and incidents, transport safety authorities in countries signatory to the Convention on International Civil Aviation. The Air Navigation Commission (ANC) is the techn ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nordic Countries
The Nordic countries (also known as the Nordics or ''Norden''; ) are a geographical and cultural region in Northern Europe, as well as the Arctic Ocean, Arctic and Atlantic Ocean, North Atlantic oceans. It includes the sovereign states of Denmark, Finland, Iceland, Norway and Sweden; the autonomous administrative division, autonomous territories of the Faroe Islands and Greenland; and the autonomous region of Åland. The Nordic countries have much in common in their way of life, History of Scandinavia, history, religion and Nordic model, social and economic model. They have a long history of political unions and other close relations but do not form a singular state or federation today. The Scandinavism, Scandinavist movement sought to unite Denmark, Norway and Sweden into one country in the 19th century. With the dissolution of the union between Norway and Sweden (Norwegian independence), the independence of Finland in the early 20th century and the 1944 Icelandic constitution ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
