- 行业: Weather
- Number of terms: 60695
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The American Meteorological Society promotes the development and dissemination of information and education on the atmospheric and related oceanic and hydrologic sciences and the advancement of their professional applications. Founded in 1919, AMS has a membership of more than 14,000 professionals, ...
A limb sounding instrument that was first flown as a Small Applications Explorer Mission in 1979. Since this initial mission, a series of SAGE instruments have been flown on a variety of satellites. In all cases, the SAGE instruments measure vertical profiles of aerosol and gas concentrations by measuring the extinction of sunlight during satellite sunrises and sunsets. SAGE II was launched in October 1984 on the ERBS, and SAGE III will be flown on a number of satellites as part of NASA's EOS program. Current plans call for placing SAGE III on a Russian Meteor platform, as well as on the International Space Station.
Industry:Weather
A stability index that is identical to the lifted index (LI) except that it modifies the standard 1200 and 0000 UTC soundings or numerical-model soundings by incorporating hourly surface observational data, and the characteristics of the lifted parcel are from surface values of temperature and dewpoint. The advantage of this index is that it can be computed at hourly intervals and it typically reflects short-term changes in the boundary layer. The surface-based lifted index is typically more unstable than the LI. As with the LI, thunderstorms become increasingly likely the further the surface- based lifted index decreases below a threshold of zero.
Industry:Weather
A cool layer of air adjacent to a cold surface of the earth, where temperature within that layer is statically stably stratified. SBLs can form at night over land when the earth is cooled by net loss of radiation, and they can form at any time when air moves over a relatively cooler land or water surface. Many interacting processes can occur within the SBL: patchy sporadic turbulence, internal gravity waves, drainage flows, inertial oscillations, and nocturnal jets. See nocturnal boundary layer.
Industry:Weather
Radar deployed aboard aircraft and satellites that produces a two-dimensional image of the target surface. The position of an object along the direction parallel to the movement of the observing platform is determined by the Doppler shift of the received signal. Phenomena observed by SAR include swell waves, current patterns imaged because of the varying sea surface roughness due to wave– current interaction, and oil spills and natural films that appear as areas of low image intensity as a result of their damping effect on centimeter-scale surface waves. See'' also'' Doppler radar, marine radar, microwave radar, high-frequency radar.
Industry:Weather
A multichannel infrared limb sounder on ''Nimbus''-7'' (launched October 1978) designed to extract vertical temperature soundings from upper atmospheric emissions.
Industry:Weather
A single channel sun photometer centered at 1 micron used to measure aerosol extinction above the earth tangent point by looking at the sun during spacecraft sunrise and sunset. SAM was initially tested as a hand-held sun photometer on ''Apollo–Soyuz'' in 1975. A follow- on SAM-II instrument was carried onboard ''Nimbus''-7'' (launched October 1978).
Industry:Weather
The range over which the pilot of an aircraft on the center line of a runway can see the runway surface markings or the lights delineating the runway or identifying its center line. RVR may be determined by an observer located at the end of the runway, facing in the direction of landing, or by means of a transmissometer installed near the end of the runway.
Industry:Weather
The encoded and transmitted report of a radar meteorological observation. These reports usually give the azimuth, distance, altitude, shape, intensity, movement, and other characteristics of echoes observed by radar.
Industry:Weather
A broadcast system for distributing various National Weather Service weather charts and information to an area that is smaller than an entire hemisphere.
Industry:Weather
The positive square root of the mean-square error. It is equal to the standard error only when the mean error is zero.
Industry:Weather
