- 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, ...
The radiant energy passing through a unit volume from all directions; units are joules per cubic meter (J m<sup>−3</sup>).
Industry:Weather
The radiant flux per unit solid angle, as from a point source; units are watts per steradian (W sr<sup>−1</sup>). See intensity.
Industry:Weather
The radiance per unit wavelength or wavenumber interval. Units are typically W m<sup>−2</sup> sr<sup>−1</sup> μm<sup>−1</sup> or W m<sup>−2</sup> sr<sup>−1</sup>(cm<sup>−1</sup>)<sup>−1</sup>.
Industry:Weather
The quantity of water evaporated per unit area, per unit time from a continuous, uniform area of grass with a fixed height of 0. 12 m, an albedo of 0. 23, and a surface resistance of 69 s m<sup>−1</sup>; approximated by the rate of evaporation for an extensive area of 0. 08 to 0. 15 m high green grass cover of uniform height, actively growing, completely shading the ground, and not short of water.
Industry:Weather
The quality of being exactly defined. Sometimes indicated by the minimum number of significant digits required for an adequate representation of a quantity. Not the same as accuracy but often confused as such. A measurement having small random error is said to have high precision; a measurement having small systematic error or bias is said to have high accuracy.
Industry:Weather
The property of being random. Computer-generated, pseudorandom numbers are sometimes used to model the behavior of certain meteorological processes. The utilized algorithms can be tested for randomness through application of statistical procedures designed to detect unwanted correlations in the sequences of numbers produced.
Industry:Weather
The propagation of radio waves under conditions of superstandard refraction (superrefraction) in the atmosphere; that is, refraction by an atmosphere or section of the atmosphere in which the refractive index decreases with height at a rate of greater than 40 N-units per kilometer. Superstandard propagation produces greater than normal downward bending of radio waves as they travel through the atmosphere, giving extended radio horizons and increased radar coverage. It is caused primarily by propagation through layers near the earth's surface in which the dewpoint temperature is rapidly decreasing or the temperature is increasing with height. Such conditions are commonly observed near coastlines when a layer of warm dry air overlies a cool moist layer adjacent to the ocean surface. A layer in which the downward bending is greater than the curvature of the earth is a radio duct. Frequently, the general term, anomalous propagation, is used for superstandard propagation. See standard propagation, substandard propagation.
Industry:Weather
The propagation of radio energy under conditions of substandard refraction in the atmosphere; that is, refraction by an atmosphere or section of the atmosphere in which the refractive index decreases with height at a rate of less than 40 N-units per kilometer. Substandard propagation produces less than the normal downward bending, or even upward bending, of radio waves as they travel through the atmosphere, giving closer radio horizons and decreased radar and radio coverage. It occurs primarily when propagation takes place through a layer in which the specific humidity is constant or increases with height. See standard propagation, superstandard propagation.
Industry:Weather
