- 行业: 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 northern parallel of maximum solar declination, approximately 23°27′N latitude. See obliquity of the ecliptic.
Industry:Weather
The movement of liquid in a porous medium due to differences in temperature.
Industry:Weather
The movement of a substance or characteristic. Characteristics that can be transported in the atmosphere are heat (temperature), moisture, momentum, chemicals, turbulence, etc. The transport is sometimes interpreted as a flux density (characteristic per unit area per time), or as a flow rate (characteristic per time). See transport processes.
Industry:Weather
The movement of a substance or characteristic by eddy motions of the wind. See turbulent flux.
Industry:Weather
The momentum integral relation that expresses the mean stress between any two stations in terms of the difference in the velocity profiles between the stations. Also known as von Kármán's momentum integral.
Industry:Weather
The moment of a force about a given point; that is, the vector product of the position vector (from the given point to the point at which the force is applied) and the force. See mountain torque, frictional torque.
Industry:Weather
The mixing ratio of the sum of vaporous, liquid, and solid water.
Industry:Weather
The minimum contrast ''C<sub>thresh</sub>'' at which an observer can just distinguish a target object from its surroundings. Threshold contrast depends on target angular size θ, the surrounding luminance ''L<sub>s</sub>'', and the desired probability of detection (usually 50%–99%). For a given ''L<sub>s</sub>'', ''C<sub>thresh</sub>'' has a minimum value at some optimal θ (i.e., the target size that is most easily detected). Threshold contrast also varies among observers and across time for a given observer. Because detection outdoors primarily depends on luminance rather than chromaticity differences, ''C<sub>thresh</sub>'' is usually calculated from spectrally integrated luminances. For alerted observers (i.e., those expecting a target to appear) and daytime luminance levels, ''C<sub>thresh</sub>'' ranges from ∼0. 005 to 5. 0 or more. Unalerted observers may require ''C<sub>thresh</sub>'' values that are five or more times greater than those for alerted observers.
Industry:Weather
The middle portion of the daytime atmospheric boundary layer characterized by convective thermals creating vigorous turbulence in a well-mixed region of vertically uniform potential temperature, wind speed, and pollutants. This layer is above the radix and surface layers, and below the entrainment zone or capping inversion. Within it, smoke plumes are observed to loop up and down as they blow downwind. It is statically unstable, in spite of the adiabatic lapse rate.
Industry:Weather
That area, within the circulation of a wave cyclone, where the warm air is found. Traditionally, it lies between the cold front and warm front of the storm; in the typical case, the warm sector continually diminishes in size and ultimately disappears (at the surface) as the result of occlusion.
Industry:Weather
