- 行业: Weather
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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, ...
An area of high atmospheric pressure near the surface resulting from the cooling of air by a cold underlying surface, and remaining relatively stationary over the cold surface. Compare thermal low, cold high; see glacial anticyclone.
Industry:Weather
An approximate technique for handling the complexity of monochromatic radiative transfer in atmospheric models. The technique reduces the directionality of the problem to an upwelling and a downwelling irradiance, and provides moderate accuracy for reflected and transmitted irradiances with little computational expense. Several variations of the two-stream technique exist, suited to different problems.
Industry:Weather
An apparatus, used in studying soil temperatures, for measuring the total supply of heat during a given period. It consists of a long nickel coil forming a 100-ohm resistance thermometer and a 6-volt battery, the current used being recorded on a galvanometer. The coil is attached to a rod for insertion. A mercury thermometer can be used. The instrument can also measure the heat balance in a plant cover.
Industry:Weather
An approximate psychophysical law relating various tactile sensations to the intensity of the stimulus. The law asserts that equal increments of sensation are associated with equal increments of the logarithm of the stimulus. The Weber–Fechner law applies to the detection of contrast in the problem of visual range and to many other psychophysical problems.
Industry:Weather
An anomaly of the relative zenith radiances of scattered sunlight at certain wavelengths in the ultraviolet as the sun approaches the horizon, due to the presence of the ozone layer. The ratio of radiances measured in the zenith direction at two wavelengths, one strongly absorbed by ozone, the other not so strongly absorbed, shows a steady decrease with solar zenith angle until a zenith angle of about 86°, whereupon the ratio increases. The details of this reversal can be used to determine the vertical distribution of ozone concentration.
Industry:Weather
An accessory cloud veil of great horizontal extent draped over or penetrated by cumuliform clouds. Velum occurs with cumulus and cumulonimbus. See cloud classification.
Industry:Weather
An absorption cell devised by John White in 1942 in which light traverses a small volume a large and arbitrarily variable number of times. Such a cell, which is composed of three spherical concave mirrors with the same radius of curvature, is used to increase the optical pathlength for observing weak absorption spectra, such as those of atmospheric trace gases.
Industry:Weather
An absolute pyrheliometer, developed by C. G. Abbot, in which the radiation-sensing element is a blackened water-calorimeter. It consists of a cylinder, blackened on the interior, and surrounded by a special chamber through which water flows at a constant rate. The temperatures of the incoming and outgoing water, which are monitored continuously by thermometers, are used to compute the intensity of the radiation. This instrument was built by the Smithsonian Institution but was never widely used as a standard instrument. The function of the instrument as an absolute reference is currently fulfilled by the absolute cavity radiometer.
Industry:Weather
An abbreviation of “Weather Bureau, Air Force, and Navy” used to denote observational instructions or forms that are common to the three principal meteorological agencies in the United States, or to denote certain cooperative meteorological activities or projects of the three agencies.
Industry:Weather
Amount of both weak and strong acids in water, usually expressed in milliequivalents of a strong base necessary to neutralize one liter of a water sample, using methyl-red or phenolphthalein as an indicator.
Industry:Weather
