- 行业: Weather
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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 measure of atmospheric turbidity, equal to the ratio of total optical depth to the Rayleigh optical depth. It is a function of wavelength.
Industry:Weather
A maximum in large-particle concentrations observed in the lower stratosphere between 15 and 25 km.
Industry:Weather
A long strip of cloud that sometimes lies against the southern base of Mount Etna in Sicily. It is said to herald rain. See contessa di vento.
Industry:Weather
A long fracture or separation between ice floes wide enough to be navigated by a ship. A lead may be covered by thin ice.
Industry:Weather
A local wind created by acceleration of the airflow through a gap, constriction, or channel in a mountain range or between ranges. The acceleration can result from a large-scale pressure gradient, or by Venturi acceleration through a constricting passage. Pressure gradients from large-scale processes can occur when a large- scale anticyclone lies on one side of the barrier, as in the case of canyon or Wasatch winds, or when a cold front impinges on a mountain barrier with a gap in it and the cold air mass forces its way through the gap, as in the case of the tehuantepecer. Other jet-effect winds include the düsenwind, the kossava, and gap winds. See also mountain-gap wind.
Industry:Weather
A level in the atmosphere throughout which the horizontal velocity divergence is zero. Although in some meteorological situations there may be several such surfaces (not necessarily level), the level of nondivergence usually considered is that midtropospheric surface that separates the major regions of horizontal convergence and divergence associated with the typical vertical structure of the migratory cyclonic-scale weather systems. Interpreted in this manner, the level of nondivergence is usually assumed to be in the vicinity of 500 mb. The assumption of such a level in theoretical work facilitated the construction of early models in numerical forecasting.
Industry:Weather
A layer, assumed to be at rest, at some depth in the ocean. This implies that the isobaric surfaces within the layer are level, and hence they may be used as reference surfaces for the computation of absolute gradient currents. This same concept can define a level of no motion or a surface of no motion.
Industry:Weather
A layer in which the fluid undergoes smooth, nonturbulent flow. It is found between any surface and a turbulent layer above. See laminar boundary layer, laminar flow.
Industry:Weather
A law governing the angular dependence of emitted or reflected radiation from an idealized surface. The radiation emitted from or reflected by a surface obeying Lambert's law is unpolarized and has a radiance that is constant with angle, or isotropic. Such surfaces are variously termed Lambertian or diffuse surfaces, reflectors, or emitters. They may also be termed perfectly diffusing radiators or reflectors. This law is sometimes called Lambert's cosine law to distinguish it from the Bouguer–Lambert law.
Industry:Weather
