- 行业: Weather
- Number of terms: 60695
- Number of blossaries: 0
- Company Profile:
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, ...
An international code assigned to a lightship to identify it as the source of meteorological observations. Lightships are considered fixed observation locations to distinguish them from ships that are under way. See ship synoptic code.
Industry:Weather
An interfacial region in which flow is smooth and nonturbulent. Above a surface, a laminar layer will develop and fluid velocity will increase with distance from the surface, but not indefinitely. At some point, flow will become turbulent, with the laminar sublayer separating the turbulent layer from the surface. In the real world, most laminar boundary layers are extremely thin (order of 1 mm), but can be of biological importance, for example, next to plant leaves or as invertebrate refuges in streams.
Industry:Weather
An integrated array of lightning direction finders that provide information for trigonometric location of cloud-to-ground lightning discharges. Timing and direction information from individual receivers are combined to provide evolving maps of lightning occurrences across vast regions that sometimes reach beyond the range of storm surveillance radars. See sferics receiver.
Industry:Weather
An instability that can be described (to first-order accuracy) by linear (or tangent linear) equations.
Industry:Weather
An idealized vortex in an unbounded fluid with uniform vorticity inside an elliptical patch and zero vorticity outside. For an ellipse with semiaxes a and b and vorticity ω in its interior, it rotates steadily with angular velocity ω(ab/(a + b)2).
Industry:Weather
An idealization for the atmospheric boundary layer that assumes uniform (well mixed) values with height within the boundary layer, capped by a discontinuity (or jump) at the top of the boundary layer. Another name for this approach is a slab model because the uniform part of the boundary layer behaves in a similar way to a uniform slab of material. Such jump or step models are reasonable simplifications for the convective boundary layer when vigorous thermals tend to keep the boundary layer well mixed, but are poor idealizations for statically stable and neutral boundary layers.
Industry:Weather
An explicit numerical approximation to the time evolution of fluid flows that is constructed through Taylor expansions to yield second-order truncation error using only two consecutive time levels. The resulting approximation introduces a diffusive damping term that helps control nonlinear computational instability and may be useful for equations with shock discontinuities.
Industry:Weather
An expert system. Those who prefer the term “expert system” emphasize the necessity of encapsulating the human expert's knowledge and way of utilizing that knowledge. Advocates of “knowledge-based systems” emphasize the importance of the knowledge itself, rather than its source or the type of reasoning employed.
Industry:Weather
