- Industry: 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, ...
With respect to aviation weather observations, a group of such observations transmitted in prescribed order by stations on the same communications circuit.
Industry:Weather
The spreading of frequencies of a spectral line as a consequence of interactions between molecules. Although the term “pressure broadening” is frequently encountered and is respectable, it is misleading in that pressure per se has nothing fundamentally to do with pressure broadening. At a fixed temperature, the number density of gas molecules is proportional to pressure. The greater the number density, the smaller the average separation between molecules, and hence the greater the potential energy of intermolecular interaction. Thus pressure is merely a surrogate for interaction (collision).
Industry:Weather
An array of clouds and precipitation associated with a cyclonic- scale feature of atmospheric circulation. Cloud systems display typical patterns and continuity, the analysis of which is termed nephanalysis.
Industry:Weather
In meteorology, a surface along which the atmospheric pressure is everywhere equal at a given instant.
Industry:Weather
An array of clouds and precipitation associated with a cyclonic- scale feature of atmospheric circulation. Cloud systems display typical patterns and continuity, the analysis of which is termed nephanalysis.
Industry:Weather
In meteorology, a surface along which the atmospheric pressure is everywhere equal at a given instant.
Industry:Weather
Without qualification, usually means the primary cosmic rays of extra-terrestrial origin that continually bombard the earth and consist mostly of high-energy protons, about 9% helium and heavier nuclei, a small percentage of electrons, and some gamma rays. The energies of cosmic rays are well in excess of billions of electron volts. Secondary cosmic rays result from interactions between primary rays and atoms in the earth's atmosphere. Most cosmic rays probably originate from the Milky Way galaxy, but a small fraction come from the sun as evidenced by diurnal variations in the cosmic ray flux.
Industry:Weather
A general area of high atmospheric pressure that, on mean charts of sea level pressure, is seen to overlie a continent during the winter. The only really pronounced example of this is the Siberian high. Compare glacial anticyclone.
Industry:Weather
A cloudlike streamer frequently observed to form behind aircraft flying in clear, cold, humid air. Condensation trails may persist and encourage the formation of a layer of cirrus clouds. Condensation trails may form by either of two distinct processes. First, addition of water vapor to the swept path of the aircraft inevitably accompanies exhaust of combustion products from the engines. If the humidifying effect of this addition overbalances the concomitant addition of the heat of combustion, exhaust trails may form depending on mixing with air from the environment. The thermodynamics of this process is such that the effect becomes important only for rather low temperatures of the order of those encountered near the tropopause, so this type of condensation trail is only usually observed for high-altitude flight. On occasion, exhaust provides needed condensation nuclei, but this effect has not been fully investigated. Second, in air that is clear, but almost fully saturated, the aerodynamic pressure reduction that accompanies flow of air around propeller tips and around wingtips can so cool the air as to induce condensation and form aerodynamic trails. The latter propeller-tip trails and wingtip trails are seldom as dense as are exhaust trails. Under some conditions the pressure reduction lowers the temperature below that for homogeneous condensation of ice and the trail consists of ice particles even at ambient temperatures as warm as −15°C. Wingtip trails only occur with aircraft of such heavy wing-loading as to yield very strong tip vortex circulations. Interceptor planes pulling out of dives, and hence imposing temporarily heavy wing-loading, may produce transient tip vortex trails. Faint vortex trails may appear aft of the corners of flaps during aircraft landings.
Industry:Weather
A general area of high atmospheric pressure that, on mean charts of sea level pressure, is seen to overlie a continent during the winter. The only really pronounced example of this is the Siberian high. Compare glacial anticyclone.
Industry:Weather
