- 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, ...
1. In radiation, See scattering. 2. A sky coverage of 1/8 through 4/8. In U. S. Weather observing procedures, this is reported with the contraction “SCT. ”
Industry:Weather
1. In radar terminology, an echo from a point target. It originally stemmed from the appearance of these types of echoes on A-scopes and R-scopes. 2. On weather maps, the triangles or half-circles along fronts that point in the direction of frontal movement.
Industry:Weather
1. In meteorology, the temperature of the air near the surface of the earth; almost invariably determined by a thermometer in an instrument shelter. 2. In oceanography, the temperature of the layer of seawater nearest the atmosphere. See sea surface temperature.
Industry:Weather
1. In meteorology, the condition existing in a given portion of the atmosphere (or other space) when the relative humidity is greater than 100%, that is, when it contains more water vapor than is needed to produce saturation with respect to a plane surface of pure water or pure ice. Such supersaturation does develop because frequently there is no “plane surface of pure water (or ice)” available. In the absence of water surfaces and in the absence of condensation nuclei or any wettable surfaces, phase change from vapor to liquid cannot occur due to the free energy barrier imposed by the surface free energy of the embryonic droplets that would then have to form by spontaneous nucleation. Humid air, purified of all foreign nuclei, can be expanded in cloud chambers to relative humidities of the order of 400% without any condensation taking place. Cloud condensation occurs in our atmosphere at relative humidities near 100% only because nature provides an abundance of condensation nuclei. 2. In physical chemistry, the condition existing in a solution when it contains more solute than is needed to cause saturation. Thermodynamically, this type of supersaturation is closely allied to supersaturation of a vapor since the solute cannot crystallize out in solutions free from impurities or seed crystals of the solute.
Industry:Weather
1. In geophysics, any penetration of the natural environment for scientific observation. 2. In meteorology, same as upper-air observation. However, a common connotation is that of a single complete set of radiosonde observations. 3. The measurement of the depth of water beneath a vessel.
Industry:Weather
1. In general, the outer boundary of a snow-covered area. It has at least two specific applications: 1) the actual lower limit of the snow cap on high terrain at any given time; 2) the ever-changing equatorward limit of snow cover, particularly in the Northern Hemisphere winter. 2. Same as firn line. See climatic snow line.
Industry:Weather
1. In general, pertaining to or affording an overall view. In meteorology, this term has become somewhat specialized in referring to the use of meteorological data obtained simultaneously over a wide area for the purpose of presenting a comprehensive and nearly instantaneous picture of the state of the atmosphere. Thus, to a meteorologist, “synoptic” takes on the additional connotation of simultaneity. 2. A specific scale of atmospheric motion with a typical range of many hundreds of kilometers, including such phenomena as cyclones and tropical cyclones. Compare mesoscale.
Industry:Weather
1. In general, any object that reflects incident energy; usually a device designed for specific reflection characteristics. 2. The part of a radio or radar antenna system that focuses and directs the transmitted wave.
Industry:Weather
1. In general, any force that tends to oppose motion. 2. Same as drag. 3. In electricity, the opposition offered by a substance to the passage of an electric current; the reciprocal of conductance. By virtue of the resistance, a portion of the electrical energy is converted into heat. See conductivity.
Industry:Weather
1. In astronomy, the arrangement of the earth, sun, and another planet or the moon in which the angle subtended at the earth between the sun and the third body, in the plane of the ecliptic, is 90°. The first and third quarters of the moon are positions of quadrature. See'' also'' conjunction, opposition. 2. In radar systems, an orthogonal relationship between two coherent signals in which the phase of one signal is offset by 90° from the phase of the other. Two signals in quadrature may be regarded as a single complex signal.
Industry:Weather
