- Settore: 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, ...
The comprehensive study of the physics, chemistry, and dynamics of the earth's atmosphere, from the earth's surface to several hundred kilometers; this usually includes atmospheric chemistry, aeronomy, magnetospheric physics, and solar influences on the entire region.
Industry:Weather
The pressure exerted by the atmosphere as a consequence of gravitational attraction exerted upon the “column” of air lying directly above the point in question. As with any gas, the pressure exerted by the atmosphere is ultimately explainable in terms of bombardment by gas molecules; it is independent of the orientation of the surface on which it acts. Atmospheric pressure is one of the basic meteorological elements. It is measured by many varieties of barometer and is expressed in several unit systems. The most common unit used is the millibar (1 millibar equals 1000 dynes cm−2). Unique to the science of meteorology is the use of inches (or millimeters) of mercury, that is, the height of a column of mercury that exactly balances the weight of the column of atmosphere the base of which coincides with that of the mercury column. Also employed are units of weight per area and units of force per area. A standard atmosphere has been defined in terms of equivalence to each of the above unit systems, and it is used as a unit itself. See actual pressure, station pressure, sea level pressure.
Industry:Weather
1. The difference between the angular positions of the image and object of a celestial object that results from refraction in the earth's atmosphere. Astronomical refraction is greatest near the horizon where it normally exceeds a solar diameter. Consequently, we see the image of the sun above the horizon even though the sun itself is below, and this extends the length of the day measurably at both ends. 2. A variety of phenomena that result from the refraction of celestial light by the earth's atmosphere. It is distinguished from the term terrestrial refraction, which is used when the source is within our atmosphere.
Industry:Weather
An accounting of radiant energy loss or gain by the atmosphere for some specified time and place. The main components are the loss of longwave radiant energy to space, a net gain (usually) of longwave radiation from the surface, and a gain of energy due to the absorption of shortwave radiation, primarily by water vapor absorption. On a long-term average, the global atmospheric radiation budget is ≈ −100 W m−2. This loss of energy is made up by the transfer of sensible and latent heat from the surface.
Industry:Weather
1. The study of all radiative processes affecting the earth's atmosphere. This discipline examines the absorption, emission, and scattering of electromagnetic radiation within the atmosphere; the nature and distribution of incident solar radiation at the top of the atmosphere; and the reflection and emission from the surface at the bottom of the atmosphere. The two main areas of importance of atmospheric radiation to meteorology are 1) the effect of radiative heating or cooling on temperature, thereby helping to define the basic structure of the earth's climate system, and 2) use of the spectral, angular, or polarization information content in measured radiation to deduce properties of the atmosphere or surface (i.e., remote sensing). See also solar radiation, terrestrial radiation. 2. Longwave radiation emitted by the atmosphere.
Industry:Weather
The pressure exerted by the atmosphere as a consequence of gravitational attraction exerted upon the “column” of air lying directly above the point in question. As with any gas, the pressure exerted by the atmosphere is ultimately explainable in terms of bombardment by gas molecules; it is independent of the orientation of the surface on which it acts. Atmospheric pressure is one of the basic meteorological elements. It is measured by many varieties of barometer and is expressed in several unit systems. The most common unit used is the millibar (1 millibar equals 1000 dynes cm−2). Unique to the science of meteorology is the use of inches (or millimeters) of mercury, that is, the height of a column of mercury that exactly balances the weight of the column of atmosphere the base of which coincides with that of the mercury column. Also employed are units of weight per area and units of force per area. A standard atmosphere has been defined in terms of equivalence to each of the above unit systems, and it is used as a unit itself. See actual pressure, station pressure, sea level pressure.
Industry:Weather
As commonly used in weather observing practice, an observable occurrence of particular physical (as opposed to dynamic or synoptic) significance within the atmosphere. Included are all hydrometeors (except clouds, which are usually considered separately), lithometeors, igneous meteors, and luminous meteors. From the viewpoint of weather observations, thunderstorms, tornadoes, waterspouts, and squalls are also included. The above usage excludes such “phenomena” as the local or large-scale characteristics of wind, pressure, and temperature; it also excludes clouds, although it includes many products of cloud development and composition. In aviation weather observation, atmospheric phenomena are divided into two categories: weather and obstructions to vision.
Industry:Weather
A minor but important constituent (chemical symbol O3) of the earth's atmosphere. While it is essential for life as we know it today, it is also a toxic gas that can result in significant physiological and ecological damage if exposures exceed critical limits. In both the stratosphere and troposphere, ozone concentration levels depend on many linked chemical and meteorological mechanisms, which vary significantly with space and time. Human pollutant emissions often perturb these linkages, resulting in significant increases or decreases in ozone concentration. While many facets of ozone's atmospheric behavior are well understood, a large number of important uncertainties remain, the resolution of which will require substantial combined efforts by the meteorological and chemical communities. See air pollution.
Industry:Weather
The study of the optical characteristics of the atmosphere or products of atmospheric processes. The term is usually confined to visible and near visible radiation. But, unlike meteorological optics, it routinely includes temporal and spatial resolutions beyond those discernible with the naked eye.
Industry:Weather
A model for simulating or predicting the behavior of the atmosphere.
Industry:Weather
