- 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, ...
A problem-solving system using a rule-based architecture consisting of a knowledge base of rules and general facts, a working memory of facts concerning the current case, and an inference engine for manipulating both. It is a type of expert system or knowledge-based system.
Industry:Weather
A principle used in forecasting the thickness of a layer between two given constant-pressure surfaces; more commonly used prior to the advent of numerical forecasting techniques. In practical use of the principle, specific thicknesses are considered to be associated with corresponding points on the lower of the two constant-pressure surfaces (the upper one can also be used). A prognostic chart is prepared for the lower surface and the assumption is made that the thickness of the layer at the corresponding points is unchanged at the same corresponding points on the prognostic map. The prognostic thickness chart is then constructed from thickness values at the corresponding points.
Industry:Weather
A popular nautical term for the stormy ocean regions between 40° and 50° latitude. It nearly always refers to the Southern Hemisphere, where there is an almost completely uninterrupted belt of ocean with strong prevailing westerly winds.
Industry:Weather
A porous paper wick atmometer. The instrument consists of a graduated tube, closed at one end, that is filled with distilled water and then covered with a larger circular piece of filter paper held in place by a disc and collar arrangement. In operation the instrument is inverted so that the distilled water is in contact with the filter paper. The amount of evaporation that occurs during an interval of time is determined by noting the change in level of the meniscus of the water. See Dines anemometer, Pitot-tube anemometer; Compare Venturi tube.
Industry:Weather
A pressure-tube anemometer, consisting of a Pitot tube mounted on the windward end of a wind vane. See'' also'' Dines anemometer.
Industry:Weather
A pressure fluctuation, usually in the range of audible frequencies, resulting from a displacement of a gas, liquid, or solid, that can be detected by a mechanical or electromechanical transducer (e.g., a barometer, microphone, or the human ear).
Industry:Weather
A one-parameter, discrete frequency distribution giving the probability that ''n'' points (or events) will be (or occur) in an interval (or time) ''x'', provided that these points are individually independent and that the number occurring in a subinterval does not influence the number occurring in any other nonoverlapping subinterval. It has the form ''P''(''n'', ''x'') = ''e''<sup>−κ''x</sup>''(κ''x'')''<sup>n</sup>''/''n''!. The mean and variance are both κ''x'', and κ is the average density (or rate) with which the events occur. When κ''x'' is large, the Poisson distribution approaches the normal distribution. The binomial distribution approaches the Poisson when the number of events ''n'' becomes large and the probability of success ''p'' becomes small in such a way that ''np'' → κ''x''. The Poisson distribution arises in such problems as radioactive and photoelectric emissions, thermal noise, service demands, and telephone traffic.
Industry:Weather
A portion of a stream defined either between its beginning and a confluence, or between two confluences.
Industry:Weather
A positive discharge lowers positive charge to the ground via a lightning flash. The flash may be initiated in the cloud or from the ground.
Industry:Weather
A portion (one-half) of a modon, such as a blocking event in the midlatitude planetary wave pattern.
Industry:Weather
