- 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 approximation to the equations of motion whereby it is assumed that the fluid is homogeneous and horizontal scales of interest are much larger than the depth of the fluid. See shallow water wave.
Industry:Weather
An approximation used in many radiation models that depict the atmosphere as being only one-dimensional and bounded at the top and bottom by horizontal plane surfaces.
Industry:Weather
An approximation to the equations of motion for very large length scales, of the order of the earth's radius, obtained by suppressing nonlinear advection terms from the momentum equations. The remaining equations may be viscous, are hydrostatic, and include full thermodynamics.
Industry:Weather
An antenna employing a reflector in the form of a paraboloid. Common in weather radar, such an antenna produces collimated radiation from a feed at the focus, providing high gain and narrow beamwidth.
Industry:Weather
An antenna that has a radiation pattern determined by the relative phases and amplitudes of the currents on the individual antenna elements. The direction of the antenna pattern can be steered by properly varying the relative phases of those elements.
Industry:Weather
An apparatus to effect dispersion of radiation and visual display of the spectrum obtained.
Industry:Weather
An anemometer that measures the three components of the wind vector by means of an array of pressure ports bored in a sphere. A Pitot tube is located in a venturi bored through the center of the sphere and up to 12 auxiliary ports are arranged on the surface of the sphere.
Industry:Weather
An anemometer that measures linear components of the wind vector by determining the effect of the wind on transit times of acoustic pulses transmitted in opposite directions across known paths. It operates on the principle that the propagation velocity of a sound wave in a moving medium is equal to the velocity of sound with respect to the medium plus the velocity of the medium. The wind velocity vector is determined by measuring the wind speed along three independent linear paths, for example, three orthogonal paths. The sonic anemometer is an absolute instrument and has the advantages of a very short time constant and an absence of moving mechanical parts.
Industry:Weather
An analysis method usually using the nondimensional equations to determine which terms are dominant for a particular phenomenon or situation so that the smaller terms can be neglected, resulting in a simplified set of equations. For example, the quasigeostrophic equations were derived by a scale analysis.
Industry:Weather
Also known as a multicast, this is a communications system involving one source that transmits a signal that is received at multiple destinations. For example, television broadcasts are an example of a point-to-multipoint communication.
Industry:Weather
