- المجال: Weather
- Number of terms: 60695
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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 radiation scale for measurement of solar exitance (irradiance). Prior to 1956, the Ångström Scale (ÅS) (1905) and Smithsonian Scale (SS) (1913) were used. Each scale was calibrated against a different radiation detector (i.e., the Ångström compensation pyrheliometer and water-stirred pyrheliometer, respectively), and yielded slightly different values for the irradiance, with the ÅS reading roughly 3. 5% lower than the SS. The International Pyrheliometric Scale (IPS), defined in 1956, represented a numerical compromise between these two scales. In 1975, the IPS was replaced by the Absolute Radiation Scale (ARS). The ARS is calibrated against six absolute cavity radiometers maintained at the World Radiation Center in Davos, Switzerland. The variation among the six radiometers is about 0. 3%. The IPS was found to give measured irradiance levels that were about 2%–3% percent lower than the more precise ARS.
Industry:Weather
1. The state of a column of air in the atmosphere when it has a superadiabatic lapse rate of temperature (i.e., greater than the dry-adiabatic lapse rate). An air parcel displaced vertically would be accelerated in the direction of the displacement. The kinetic energy of the parcel would consequently increase with increasing distance from its level of origin. See parcel method, conditional instability, absolute stability. 2. (Also called mechanical instability. ) The state of a column of air in the atmosphere when its lapse rate of temperature is greater than the autoconvective lapse rate. In such a column the air density would increase with elevation. See also autoconvection.
Industry:Weather
An instrument the calibration of which can be determined by means of simple physical measurements on the instrument.
Industry:Weather
A line that has the properties of both constant pressure and constant height above mean sea level. Therefore, it can be any contour line on a constant-pressure chart, or any isobar on a constant-height chart.
Industry:Weather
(Also called absolute linear momentum. ) The (linear) momentum of a particle as measured in an absolute coordinate system; hence, in meteorology, the sum of the (vector) momentum of the particle relative to the earth and the (vector) momentum of the particle due to the earth's rotation.
Industry:Weather
Highest daily maximum temperature observed during a given calendar month over a specified period of years.
Industry:Weather
