- 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, ...
Two observed states of the atmosphere that are very close by some measure, also applied to states of a model. Formal measures of closeness include anomaly correlation, root-mean-square distance, and covariance. Usually one expects analogs to occur only during the same time of year. Atmospheric analogs that are close compared to current levels of observational error are unlikely to be found unless one studies a single variable confined to a very small area (≤1000 km radius), or otherwise reduces the degrees of freedom to a very small number (≤3). Analogs have a practical application in specifying the surface weather from a 3D atmospheric state produced by NWP and in short- term climate prediction for forecasts ranging from a month to several seasons. Analogs are also of interest in research related to predictability, short-term forecasts and error growth, cluster analysis, and estimates of dimensionality of the atmospheric attractor. When natural analogs are poor, improvements have been sought by combining several of them, by using anti-analogs (antilogs), and by constructing an artificial close analog by some objective weighted averaging of a set of previously observed states (constructed analogs). See MOS, perfect prognosis method.
Industry:Weather
An empirical forecast model based on the use of analogs. The observed states subsequent to a previously observed analog of the current observed state can be used as a forecast.
Industry:Weather
A method of predicting future climate by comparison with a historical situation, such as a paleoclimate state, in which the climatic forcing had features similar to those anticipated in the future.
Industry:Weather
A method of forecasting that involves searching historical meteorological records for previous events or flow patterns similar to the current situation, then making a prediction based on those past events or patterns.
Industry:Weather
1. A form of data display in which values are shown graphically. 2. A form of computing in which values are represented by directly measurable quantities, such as voltage or resistance. Analog computing methods contrast with digital methods in which values are treated numerically.
Industry:Weather
A front at which the warm air is ascending the frontal surface up to high altitudes. With anafronts, precipitation may occur to the rear of the front and is sometimes associated with cyclogenesis. Compare katafront.
Industry:Weather
(Also called anabaric. ) Pertaining to an increase in atmospheric pressure.
Industry:Weather
1. The absence of oxygen, preventing normal life for organisms that depend on oxygen. 2. Water with insufficient dissolved oxygen to support aerobic bacteria.
Industry:Weather
A current through the Bering Strait that carries low-salinity water of Pacific origin into the Arctic Ocean. It is concentrated on the Siberian side with speeds near 0. 3 m s−1 and varies little with season. During winter it is augmented by additional flow from the Sphanberg Strait. With a total transport of less than 0. 5 Sv (0. 5 × 106 m3s−1), the Anadyr Current contributes little to the mass balance of the World Ocean but is essential to its freshwater budget since the salinity of the North Pacific is so much lower than that of the North Atlantic. In terms of freshwater transport the modest Anadyr Current is equivalent to several Amazon Rivers.
Industry:Weather
In mountain meteorology, an upslope wind driven by heating (usually daytime insolation) at the slope surface under fair-weather conditions. The mechanism of the anabatic wind can be described as follows. The warm surface heats a vertical column of the atmosphere starting at the slope surface and reaching up to a few hundred meters deep. This column is warmer than the column at the same levels over the valley or plain, resulting in hydrostatic low pressure over the slope relative to over the valley or plain. The horizontal pressure gradient, maximized at the slope surface, drives an acceleration directed toward the slope, or up the slope. Although the pressure-gradient forcing is at its maximum at the slope, surface friction causes the peak in the anabatic wind speeds to occur above the surface, often by several tens of meters; if the surface heating is strong, however, the momentum will tend to be vertically mixed. Speeds in the mountain–valley anabatic flow layer are often 3–5 m s−1. Because heating at the surface promotes deeper mixing than cooling does, the heated layer, often occurring as a convective or mixed layer, is generally deeper than a cooled or katabatic layer. Slopes occur on many scales, and consequently anabatic flows also occur on many scales. At local scales anabatic winds are an along-slope component of mountain–valley wind systems. At scales ranging from the slopes of individual hills and mountains to the slopes of mountain ranges and massifs, anabatic flows represent the daytime component of mountain–plains wind systems. In general usage, this term does not suffer from the multiplicity of meanings that katabatic wind does.
Industry:Weather
