- Industry: 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, ...
Same as x-ray; rarely used these days. X-ray was the coinage of Wilhelm Röntgen, who discovered them.
Industry:Weather
The wind direction most frequently observed during a given period. The periods most frequently used are the observational day, month, season, and year. Methods for determination vary from a simple count of periodic observations to the computation of a wind rose. Compare resultant wind.
Industry:Weather
The angle between any given ray of scattered radiation and the incident ray. Convention varies as to whether this angle is measured with respect to the direction in which the incident radiation was advancing or with respect to the direction from scatterer to radiation source. See scattering.
Industry:Weather
The force due to differences of pressure within a fluid mass. The (vector) force per unit volume is equal to the pressure gradient, −∇''p'', and the force per unit mass (specific force) is equal to the product of the volume force and the specific volume, −α∇''p''. In the atmosphere, the vertical component of this force is of the order of 10<sup>4</sup> times the horizontal component; in meteorological literature the term “pressure force” usually refers only to the latter horizontal pressure force.
Industry:Weather
Strong straight-line winds associated with nontornadic outflow from strong thunderstorms. Used by Canadian meteorologists, particularly in Manitoba; no longer used in the United States. See'' also'' derecho, downburst.
Industry:Weather
Aviation weather communications code word for radar report. See radar meteorological observation.
Industry:Weather
An instrument for measuring the transmissivity of the atmosphere; a type of transmissometer. It consists of a constant-intensity collimated light source located at a suitable distance from a photoelectric cell. Variation in the turbidity of the atmosphere causes changes in the intensity of the light received by the photo cell, thereby varying its electrical output.
Industry:Weather
An ice crystal usually having an aspect ratio greater than 2 and as much as 100 and with hexagonal symmetry, although trigonal (threefold) and occasionally other symmetries occur. As such crystals fall through the clouds in which they form, they may encounter conditions causing them to develop dendritic extensions, that is, become plane-dendritic crystals.
Industry:Weather
A series of fine weakly colored bows that can frequently be seen just inside the primary rainbow. When formed in rain showers, where there is a broad distribution of drop sizes, these bows are mainly seen near the top of the rainbow arch, but fade toward the vertical portions of the primary bow. They owe their name (beyond the prescribed number) to the fact that an explanation of rainbows based upon a treatment of light as a series of rays is incapable of accounting for them. However, when light is treated as a wave, the supernumerary bows become higher-order interference maxima, for which the primary bow is but the first maximum. In this sense, the supernumerary bows are as much a part of the primary bow as are, say, its colors.
Industry:Weather
The lowest atmospheric layer immediately adjacent to a surface covered with relatively large roughness elements such as stones, vegetation, trees, or buildings. The roughness sublayer extends from the surface up to about two to five times the height of the roughness elements and includes the canopy layer. Within the roughness sublayer the flow is three-dimensional, since it is dynamically influenced by length scales of individual roughness elements and surface layer scaling cannot be expected to apply. Compare aerodynamic roughness length.
Industry:Weather
