NationMaster - Encyclopedia: Contrail

Contrails are condensation trails (sometimes vapour trails): artificial cirrus clouds made by the exhaust of aircraft engines or wingtip vortices which precipitate a stream of tiny ice crystals in moist, frigid upper air. Contrary to appearances, they are not air pollution as such, though might be considered visual pollution. Image File history File linksMetadata Download high resolution version (1900x2830, 642 KB) original description: Source: [1] File links The following pages link to this file: Contrail Pratt & Whitney Pratt & Whitney JT3D Portal:Aviation/Selected picture archive C-141 Starlifter Wikipedia:Featured pictures candidates/September-2005 Wikipedia:Featured picture candidates/C... Image File history File linksMetadata Download high resolution version (1900x2830, 642 KB) original description: Source: [1] File links The following pages link to this file: Contrail Pratt & Whitney Pratt & Whitney JT3D Portal:Aviation/Selected picture archive C-141 Starlifter Wikipedia:Featured pictures candidates/September-2005 Wikipedia:Featured picture candidates/C... C-141 Starlifter A C-141 Starlifter leaves a vapor trail over Antarctica // The Lockheed C-141 Starlifter is a military strategic airlifter in service with the United States Air Force. ... Image File history File linksMetadata Download high resolution version (811x660, 255 KB) Aircraft in cruise at roughly 35,000 feet above Bristol, England. ... Image File history File linksMetadata Download high resolution version (811x660, 255 KB) Aircraft in cruise at roughly 35,000 feet above Bristol, England. ... NOAA image from http://www. ... NOAA image from http://www. ... Image File history File links Contrails over Nova Scotia, see also the http://commons. ... Image File history File links Contrails over Nova Scotia, see also the http://commons. ... An Earth observation satellite, ERS 2 For other uses, see Satellite (disambiguation). ... Motto: Munit Haec et Altera Vincit (Latin: One defends and the other conquers) Official languages none (English, French, Gaelic) Flower Mayflower Tree Red Spruce Bird Osprey Capital Halifax Largest city Halifax Lieutenant-Governor Mayann E. Francis Premier Rodney MacDonald (PC) Parliamentary representation - House seats - Senate seats 11 10 Area Total... Categories: US geography stubs ... World map showing Europe A satellite composite image of Europe Europe is one of the seven traditional continents of the Earth. ... Image File history File linksMetadata Download high-resolution version (1024x768, 84 KB) Author: Robert C. VanWaning (myself). ... Image File history File linksMetadata Download high-resolution version (1024x768, 84 KB) Author: Robert C. VanWaning (myself). ... A cirrus cloud is a type of cloud composed of ice crystals and characterized by thin, wisplike strands, often accompanied by tufts. ... Image File history File linksMetadata Download high-resolution version (1024x768, 52 KB) Author: Robert C. VanWaning. ... Image File history File linksMetadata Download high-resolution version (1024x768, 52 KB) Author: Robert C. VanWaning. ... Cirrus can refer to: a type of cloud, cirrus cloud a car produced by DaimlerChrysler, Chrysler Cirrus a German rocket, cirrus (rocket) a trance music group, Cirrus (music group) an interbank network (ATM network) by MasterCard, Cirrus (interbank network) a British aircraft engine company, Cirrus Engine an aircraft company, Cirrus... Water vapor condensing over a cup of hot tea Condensation is the change in matter of a substance to a denser phase, such as a gas (or vapor) to a liquid. ... A cirrus cloud is a type of cloud composed of ice crystals and characterized by thin, wisplike strands, often accompanied by tufts. ... An Airbus A380, currently the worlds largest airliner An aircraft is any vehicle or craft capable of atmospheric flight. ... Wingtip vortices stream from an F-15 as it disengages from a KC-10 Extender following midair refueling. ... Snowflakes by Wilson Bentley, 1902 Ice is the name given to any one of the 14 known solid phases of water. ... Layers of Atmosphere (NOAA) Air redirects here. ... Before flue gas desulfurization was installed, the emissions from this power plant in New Mexico contained excessive amounts of sulfur dioxide. ... Visual pollution is the term given to unattractive visual elements of a vista, a landscape, or any other thing that a person might want to look at. ...

As NASA states [1], The National Aeronautics and Space Administration (NASA) is an agency of the United States Government, responsible for that nations public space program. ...

Condensation from engine exhaust

An aircraft engine's exhaust increases the amount of moisture in the air, which can push the water content of the air past saturation point. This causes condensation to occur, and the contrail to form.Aviation fuel such as petrol. When the fuel is burned, the carbon combines with oxygen to form carbon dioxide; the hydrogen also combines with oxygen to form water, which emerges as in the exhaust. For every gallon of fuel burned, approximately one gallon of water is produced, in addition to the water already present as humidity in the air used to burn the fuel. At high altitudes this water vapour emerges into a cold environment, (as altitude increases, the atmospheric temperature drops) and the local increase in water vapour density condenses into tiny water droplets and/or desublimates into ice. These millions of tiny water droplets and/or ice crystals form the contrails. The energy drop (and therefore, time and distance) the vapour needs to condense accounts for the contrail forming some way behind the aircraft's engines.The majority of the cloud content comes from water trapped in the surrounding air. At high altitudes, supercooled water vapour requires a trigger to encourage desublimation. The exhaust particles in the aircraft's exhaust act as this trigger, causing the trapped vapor to rapidly turn to ice crystals. Contrails will only occur when the outside air temperature around the aircraft is at or below -57 degrees Celsius. An Airbus A380, currently the worlds largest airliner An aircraft is any vehicle or craft capable of atmospheric flight. ... Dew on a spider web The dew point or dewpoint of a given parcel of air is the temperature to which the parcel must be cooled, at constant barometric pressure, for the water vapor component to condense into water, called dew. ...

Condensation from wing-tip pressure

The wings of an airplane cause a drop in air pressure in the vicinity of the wing (this is partly what enables a plane to fly). This drop in air pressure brings with it a drop in temperature, which can cause water to condense out of the air and form a contrail but only at higher altitudes. At lower altitudes, this phenomenon is also known as "ectoplasm." Ectoplasm is more commonly seen during high energy manouvers like those of a fighter jet, or on jet liners during takeoff and landing, at areas of very low pressure, including over the wings, and often around turbo-fan intakes on takeoff. Wingtip vortices stream from an F-15 as it disengages from a KC-10 Extender following midair refueling. ...

Contrails and climate

Contrails, by affecting cloud formation, can act as a radiative forcing. Various studies have found that contrails trap outgoing longwave radiation emitted by the Earth and atmosphere (positive radiative forcing) at a greater rate than they reflect incoming solar radiation (negative radiative forcing). Therefore, the overall effect of contrails is a warming.^[1] However, the effect varies daily and annually, and overall the size of the forcing is not well known: globally (for 1992 air traffic conditions), values range from 3.5 mW/m² to 17 mW/m². Other studies have determined that night flights are most responsible for the warming effect: while accounting for only 25% of daily air traffic, they contribute 60 to 80% of contrail radiative forcing. Similarly, winter flights account for only 22% of annual air traffic, but contribute half of the annual mean radiative forcing.^[2] The generalised concept of radiative forcing in climate science is any change in the radiation (heat) entering the climate system or changes in radiatively active gases. ... Longwave radiation is a term used to describe the infrared energy emitted by the earth and atmosphere at wavelengths between about 5 and 25 micrometers. ... Solar irradiance spectrum at top of atmosphere. ...

September 11, 2001 climate impact study

It had been hypothesized that in regions such as the United States with heavy air traffic, contrails affected the weather, reducing solar heating during the day and radiation of heat during the night by increasing the albedo. The suspension of air travel for three days in the United States after September 11, 2001 provided an opportunity to test this hypothesis. Measurements did show that without contrails the local diurnal temperature range (difference of day and night temperatures) was about 1 degree Celsius higher than immediately before;^[3] however, it has also been suggested that this was due to unusually clear weather during the period.^[4] Weather is a term that encompasses phenomena in the atmosphere of a planet. ... Albedo is a ratio of scattered to incident electromagnetic radiation power. ... A sequential look at United Flight 175 crashing into the south tower of the World Trade Center The September 11, 2001 attacks (often referred to as 9/11â€”pronounced nine eleven or nine one one) consisted of a series of coordinated terrorist[1] suicide attacks upon the United States, predominantly...

See also

Aviation contributes to global warming in a number of ways, the most significant of which is the combustion of kerosene (a fossil fuel) in flight. ... A cirrus cloud is a type of cloud composed of ice crystals and characterized by thin, wisplike strands, often accompanied by tufts. ... NASA photograph showing aircraft contrails and natural clouds. ... Ship tracks can be easily seen as lines in these clouds over the Atlantic Ocean on the east coast of the United States. ... This page aims to list articles related to the natural environment. ... Meteorological phenomenon resembling some descriptions of chemtrails Chemtrails(Contrails) over London The chemtrail theory is a group of theories regarding what are claimed to be unnatural contrails from aircraft. ... For other uses, see Conspiracy theory (disambiguation). ...

References

First title page, November 4, 1869 Nature is one of the oldest and most reputable scientific journals, first published on 4 November 1869. ... A digital object identifier (or DOI) is a standard for persistently identifying a piece of intellectual property on a digital network and associating it with related data, the metadata, in a structured extensible way. ...

External links

Image File history File links Commons-logo. ... Wikimedia Commons logo by Reid Beels The Wikimedia Commons (also called Commons or Wikicommons) is a repository of free content images, sound and other multimedia files. ... Wikipedia does not have an article with this exact name. ... Wiktionary is a multilingual, Web-based project to create a free content dictionary, available in over 150 languages. ...

Categories: Aviation | Cloud types Cumulonimbus capillatus incus floating over Swifts Creek, Victoria in Australia A cloud is a visible mass of condensed droplets or frozen crystals suspended in the atmosphere above the surface of the Earth or another planetary body. ... A cirrus cloud is a type of cloud composed of ice crystals and characterized by thin, wisplike strands, often accompanied by tufts. ... Cirrus uncinus is a type of cirrus cloud. ... A KHI on the planet Saturn, formed at the interaction of two bands of the planets atmosphere Kelvin-Helmholtz instability can occur when velocity shear is present within a continuous fluid or when there is sufficient velocity difference across the interface between two fluids. ... Cirrostratus showing an extremely large halo. ... Cirrocumulus at the top of the image A Cirrocumulus is a high-altitude cirriform cloud, occurring at 20,000-40,000 ft or 6,000-12,000 m. ... A pileus (Latin for cap) is a small, horizontal cloud that can appear above a cumulus or cumulonimbus cloud, giving the parent cloud a characteristic hoodlike appearance. ... Altostratus is a cloud belonging to a class characterized by a generally uniform gray sheet or layer, lighter in color than nimbostratus and darker than cirrostratus. ... Image provided by Simon Eugster The altostratus undulatus is a type of low altocumulus cloud with signature undulations within it. ... An Altocumulus is a cloud belonging to a class characterized by globular masses or rolls in layers or patches, the individual elements being larger and darker than those of cirrocumulus and smaller than those of stratocumulus. ... The altocumulus undulatus is a mid-level cloud (about 8000 - 20,000 ft or 2400 - 6100 m), usually white or grey with layers or patches containing undulations that resemble waves or ripples in water. ... Mackerel sky over Edmonton, Alberta An altocumulus mackerel sky or mackerel sky is an indicator of moisture (the cloud) and instability (the cumulus form) at intermediate levels (2400-6100 m, 8000-20,000 ft). ... Altocumulus Castellanus is a family B type cloud. ... Lenticular clouds, technically known as altocumulus standing lenticularis, are stationary lens-shaped clouds that form at high altitudes, normally aligned at right-angles to the wind direction. ... Stratus Opacus Uniformis This article is about the meteorological phenomenon. ... Heavy nimbostratus cover. ... Cumulus humilis, with cumulus congestus on the horizon Cumulus humilis (from L humilis, humble) is what is commonly referred to as fair weather cumulus. These clouds typically occur at 500 to 1000 metres altitude and rarely reach 2000 metres. ... Cumulus mediocris (from the Latin for moderate) is a cloud form of the cumulus family, slightly larger in vertical development than Cumulus humilis. ... A group of stratocumulus clouds hanging low over the mountain valley seen from the summit of Mount Kinabalu. ... Cumulonimbus (Cb) is a type of cloud that is tall, dense, and involved in thunderstorms and other bad weather. ... A cumulonimbus incus cloud has a characteristic anvil-top shape. ... Cumulonimbus calvus is an moderately tall cumulonimbus cloud which is capable of precipitation, but has not yet reached the height where it forms into a cumulonimbus incus (anvil-top). ... Mammatus clouds in Tulsa, Oklahoma, 1973 Cumulonimbus with mammatus formed after Hurricane Catarina in Santa Catarina, Brazil, 2004 Another view of the post-Catarina mammatus formation Mammatus (also known as mamma or mammatocumulus) is a meteorological term applied to a cellular pattern of pouches hanging underneath the base of a... Cumulus congestus clouds are characteristic of unstable areas of the atmosphere which are undergoing convection. ... Pyrocumulus, or fire cumulus, is a dense cumuliform cloud usually found at an altitude of 1500 m. ... The pyrocumulonimbus (pyroCb) is a type of cloud formed above a source of heat such as a wildfire or industrial plant. ...

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