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faint diffuse illumination of the sky originating in the upper atmosphere. Although it occurs at all times of day throughout the upper atmosphere, it is most typically visible to an observer on earth on dark nights, above the horizon. The energy in the form of visible light is derived from the sun's ultraviolet light, which ionizes atoms and dissociates molecules at heights between 40 and 200 mi (64–322 km) above the earth's surface. When the fragments collide and recombine, some atoms and molecules are left with excess energy, which they release as light at characteristic wavelengths. Most prominent in the visible spectrum are the red and green light of oxygen and the yellow light of sodium. In southern and northern polar regions the airglow is often masked by the aurora (see aurora borealisaurora borealis
and aurora australis
, luminous display of various forms and colors seen in the night sky. The aurora borealis of the Northern Hemisphere is often called the northern lights, and the aurora australis of the Southern Hemisphere is known as the southern
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). Airglow hampers optical telescopic observations on earth by reducing the apparent contrast between stars and space.


(air -gloh) (nightglow) The faint everpresent glow arising in the Earth's atmosphere that is light emitted (along with infrared radiation) during the recombination of ionized atoms and molecules following collisions with high-energy particles and radiation, mainly from the Sun. Airglow interferes with optical and infrared observations of faint celestial bodies.



the luminescence of gases found in the upper atmosphere at altitudes above 70–80 kilometers; an important component of the luminescence of the night sky.

Airglow exhibits not only a continuous spectrum but also atomic emission lines of oxygen, hydrogen, and sodium and molecular bands of the hydroxyl radical, oxygen, carbon dioxide, ozone, water, and nitrogen oxides. The emission of the individual components of airglow occurs at various altitudes in strata of varying thickness. The altitude and thickness of the layers may change. One of the main energy sources for airglow is the energy of solar radiation, which causes dissociation and ionization in the upper atmosphere; the subsequent recombination of particles produces airglow.

The intensity of all the emissions depends on the degree to which the upper atmosphere is illuminated, on the density, temperature, and composition of the upper atmosphere at the altitudes where the emissions occur, on solar and geomagnetic activity, and on the latitude of the observation site. There are daily and seasonal cycles.

The mechanisms responsible for airglow have not yet been fully explained. Observations of the spectra of airglow and of variations in its intensity dependent on heliogeophysical conditions are widely used to obtain data on the composition, density, temperature, and other properties of the atmosphere at high altitudes.


Chamberlain, J. Fizika poliarnykh siianii i izlucheniia atmosfery. Moscow, 1963. (Translated from English.)



The quasi-steady radiant emission from the upper atmosphere over middle and low latitudes, as distinguished from the sporadic emission of auroras which occur over high latitudes. Also known as light-of-the-night-sky; night-sky light; night-sky luminescence; permanent aurora.
References in periodicals archive ?
In one corner of the Airglow building (currently being used as the Electronics lab) is a computer connected to a VLF (Very Low Frequency) antenna outside.
29 S-310 is the first domestic rocket aimed at conducting a comprehensive observation of airglow.
Airglow can be produced by a variety of known sources, including cosmic rays striking the upper atmosphere and chemical reactions.
Even light from the auroras or airglow (the natural nighttime glow caused by radiation from the upper atmosphere) will generate brilliantly detailed views of water, ice floes and weather patterns.
He assigns a number to the quality of sky visible--1 being an excellent dark sky with Zodiacal Band and Airglow apparent, magnitude 7-8 visible with the naked eye and the Milky Way casting shadows.
Washington, July 15 (ANI): An airglow signature in the upper atmosphere produced by a tsunami has been recorded for the first time ever by University of Illinois scientists using a camera system based in Maui, Hawaii.
The TIP photometers are among the highest sensitivity FUV airglow sensors ever flown.
Masaaki Huruhata born; a Japanese astronomer; Director of the Tokyo Astronomical Observatory; did work on meteors, variable stars, photoelectric photometry of the zodiacal light and airglow.
The Special Sensor Ultraviolet Limb Imager (SSULI) is an Earth limb-imaging spectrograph that will measure high-altitude ionospheric and thermospheric airglow profiles in the far- and extreme-ultraviolet wavelengths.
In 2001, SRI led a team that made the first observation of visible light emitted by oxygen atoms in the night airglow of Venus, offering new insight into the planet's atmosphere.
In the IGY many groups of amateurs worked on observations of the upper atmosphere (aurora, increased airglow and NLC).
From West Germany comes an Airglow Solar Spectrometer, a multipurpose device to measure solar radiation reflected from the earth's surface and clouds; radiation of solar, interplanetary and intergalactic origin that reaches the satellite directly; and the equatorial day and night airglow (observable light that originates in the high atmosphere and is associated with photochemical reactions of gases).