- 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, ...
In synoptic meteorology and in weather observing, that portion of the atmosphere that is above the lower troposphere. No distinct lower limit is set but the term can be generally applied to the levels above 850 mb. Compare upper atmosphere.
Industry:Weather
In simple terms, the horizontal distance between successive wave crests measured perpendicular to the crests. However, in a random sea, a variety of interpretations of this are possible. A commonly used definition is the so-called zero-upcrossing length, which is the horizontal distance between two successive upcrossings of the mean water level. See wave frequency, wave height, wave period.
Industry:Weather
In regions of the Middle East and North Africa, a stream bed or channel that only carries water during the rainy season. In the southwest United States, the equivalent terms would be arroyo or wash.
Industry:Weather
In radiation, the distance between periodic spatial repetitions of an electromagnetic wave at a given instant of time; used extensively to classify the nature of the radiation, since most of the interactions between radiation and matter are extremely sensitive to the wavelength of the radiation. Units are length (e.g., nm, μm, mm, cm, with conventional usage depending on which part of the electromagnetic spectrum is being considered).
Industry:Weather
In radar, the power that is transmitted from the antenna into space. For a pulsed radar, the peak power transmitted is usually much higher than the average power transmitted. The ratio of the average power to the peak power equals the duty cycle, which is the product of the pulse duration and the PRF. Compare received power.
Industry:Weather
In radar, a series of consecutive scans, either around the horizon or in a sector, that together sweep out a volume of space. Volume scans are typically performed by conducting a series of horizontal scans, each at a progressively higher elevation angle. A less common method is to conduct a series of vertical scans between the horizon and the zenith, each at a different azimuth angle. Volume scans are used to develop three-dimensional views of the reflectivity field and, in the case of a Doppler radar, the radial velocity field associated with the targets illuminated by the radar. See scanning.
Industry:Weather
In lakes, rivers, and seas, the increase in water level from still conditions due to wind.
Industry:Weather
