- 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, ...
Radiation that comes from some continuous range of directions. This includes radiation that has been scattered at least once, and emission from nonpoint sources. It is to be contrasted with parallel radiation, as from a point source. The more isotropic the radiation field, the more diffuse the radiation is considered to be.
Industry:Weather
1. The change in the direction of radiation into all directions after encountering a rough surface. Compare specular reflection. 2. Term frequently applied to the process by which solar radiation is scattered by dust and other particles suspended in the atmosphere. 3. Reflection by a diffuse reflector.
Industry:Weather
1. The transport of matter solely by the random motions of individual molecules not moving together in coherent groups. Diffusion is a consequence of concentration gradients. 2. The process of mixing fluid properties by molecular and turbulent motions. The process in turbulent flow is called turbulent or eddy diffusion. Diffusion by turbulence is much more rapid than diffusion by molecular motions. Turbulence with statistics independent of direction is called isotropic. In general, turbulence in the atmosphere and ocean is not isotropic. See diffusivity.
Industry:Weather
Downward scattered and reflected solar radiation coming from the whole hemisphere of the sky with the exception of the solid angle subtended by the sun's disk.
Industry:Weather
Any surface with irregularities so large compared to the wavelength of the incident radiation that the reflected rays are sent back in multiple directions; the opposite of a specular reflector, such as a mirror. Most natural surfaces act more like diffuse reflectors than specular reflectors. Exceptions are calm water and some ice surfaces. To be distinguished from a perfectly diffuse reflector.
Industry:Weather
In bomb ballistics, the vector difference between the wind at the bomb-release altitude and the wind at some other specific lower altitude. The differential winds are required for the computation of the differential ballistic wind.
Industry:Weather
The rate at which adjacent flow diverges along an axis oriented normal to the flow at the point in question; the opposite of confluence. The diffluence may be measured by ∂vn/∂n or V∂ψ/∂n, where V is the speed of the wind, the n axis is oriented 90° clockwise from the direction of the wind vector, vn is the wind component in the n direction, and ψ is the wind direction measured in degrees clockwise from a reference direction.
Industry:Weather
A front across which the characteristics of temperature change and wind shift are weakly defined.
Industry:Weather
A phenomenon of meteorological optics for which the approximate theory of diffraction has often been used to provide an explanation. While no phenomenon can be correctly said to have been caused by diffraction, the theory is useful as a means of gaining insight into behavior.
Industry:Weather
