- Industry: Weather
- Number of terms: 60695
- Number of blossaries: 0
- Company Profile:
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, ...
1. Same as phase speed. 2. The velocity at which a wave of given frequency and wave length advances across the ocean. See dispersion relationship.
Industry:Weather
1. Pertaining to the emission or the measurement of electromagnetic radiation. Compare luminous. 2. In describing auroras, a projected point of intersection of lines drawn coincident with auroral streamers, that is, the point from which the aurora seems to originate.
Industry:Weather
1. Radiant energy (e.g., electromagnetic, acoustic) per unit frequency (or wavelength) interval over some range of frequencies; may also be applied to any distribution function. For example, the distribution of droplet sizes in clouds is sometimes called a size spectrum. 2. Mathematically, same as spectral function.
Industry:Weather
1. Regular markings on an instrument used to allow the reading of the measured quantity or setting. 2. A factor that relates the indication of the measuring instrument to the value of the quantity. 3. An order of magnitude aid in estimating meteorological parameters (e.g., mesoscale).
Industry:Weather
1. Same as airport elevation. 2. The actual elevation of the touchdown zone of a runway. It is published on the IFR Approach Plates.
Industry:Weather
1. Pertaining to rain, or more broadly, to precipitation, particularly to an abundant amount thereof. Compare hyetal, glacial. 2. Pertaining to an interval of geologic time that was marked by a relatively large amount of precipitation; the opposite of interpluvial. This is usually applied to those periods of heavy rainfall in the lower latitudes associated with the equatorward advance of the glacierization of an ice age. Thus, a pluvial period of low latitudes generally coincides with a glacial stage of higher latitudes. During pluvial periods the surfaces of existing lakes rose to high levels. In some cases several lakes combined into great sheets of water, such as Lakes Lahontan and Bonneville in the Great Basin of the western United States.
Industry:Weather
1. Overturning, quasi-two-dimensional circulations parallel to mean wind in the layer they occupy in which individual particles move downwind in a helical motion. In the atmosphere, boundary layer rolls usually consist of alternating counterrotating helices, aligned nearly parallel to the mean boundary layer wind. When clouds are present, they form over the upwelling parts of the roll circulation. Called cloud streets, they are a good measure of roll wavelength. Typically, cloud streets are spaced at about two to three times the depth of the rolls, although larger spacings are not unusual. Several mechanisms have been proposed for forming rolls; formation and maintenance of atmospheric rolls is thought to involve both buoyancy and shear effects. In some cases, rolls are thought to result from the action of gravity waves on the boundary layer. Rolls occur in the convective boundary layer and have been observed with both stronger winds and midboundary layer wind maxima. They have also been observed for lighter winds with weaker buoyant forcing. 2. The overturning motion that results from breaking Kelvin–Helmholtz waves.
Industry:Weather
1. Modulation of a carrier signal by a train of pulses, as in pulsed radar. 2. Use of a series of pulses modulated to carry information. The modulation may involve changes of pulse amplitude, position, phase, or duration. 3. Modulation of the waveform characteristics within an individual pulse during the duration of the pulse, as in pulse compression.
Industry:Weather
1. Of a differential equation, a point at which the coefficients are not expandable in a Taylor series. 2. Of a function of a complex variable, a point at which the function does not have a derivative. 3. (Also called singularity. ) Of a flow field, a point at which the direction of flow is not uniquely determined, hence, a point of zero speed, for example, a col.
Industry:Weather
