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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, ...
probability distribution that applies to experiments involving sequences of independent trials in which only two possible outcomes (e.g., success or failure) can result on each trial.
If ''p'' is the probability of success on each trial, and ''q'' = 1 − ''p'' the probability of failure, then the probability of success occurring ''x'' times in ''n'' trials is given by the binomial distribution:
<center>[[File:ams2001glos-Be17.gif
Industry:Weather
The empirical generalization that for many so-called perfect gases, the product of pressure p and volume ''V'' is constant in an isothermal process:
<center>[[File:ams2001glos-Be19.gif
Industry:Weather
Useful for assessing the accuracy of predictions that are stated as probabilities, such as probabilities of the occurrence of precipitation,
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Industry:Weather
Radar signature of the melting layer; a narrow horizontal layer of stronger radar reflectivity in precipitation at the level in the atmosphere where snow melts to form rain. The bright band is most readily observed on range–height indicator (RHI) or time–height indicator (THI) displays.
As ice crystals fall toward warmer temperatures at lower heights, they tend to aggregate and form larger snowflakes. This growth accounts for an increase in radar reflectivity as the falling particles approach the melting level. As they cross the 0°C level, the particles begin melting from the surface inward and finally collapse into raindrops. The reflectivity maximum in the melting layer is explained partly by the difference in the value of the dielectric factor, [[File:ams2001glos-Bex02.gif
Industry:Weather
1. An approximation to the gradient Richardson number formed by approximating local gradients by finite difference across layers.
The bulk Richardson number R<sub>B</sub> is
<center>[[File:ams2001glos-Be22.gif
Industry:Weather
The vertical kinematic flux of virtual potential temperature, which when multiplied by the buoyancy parameter (''g/T<sub>v</sub>'') yields a flux that is proportional to buoyancy, that is,
<center>[[File:ams2001glos-Be25.gif
Industry:Weather
In a continuously stratified fluid, the natural frequency of the vertical oscillation of fluid parcels.
It is also called the Brunt–Väisälä frequency. Explicitly, the squared buoyancy frequency is
<center>[[File:ams2001glos-Be26.gif
Industry:Weather
A measure of the suppression of vertical turbulent motions by statically stable air.
Defined as:
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Industry:Weather
For a statically stable atmosphere, the portion of the turbulence kinetic energy spectrum at wavelengths longer than those in the inertial subrange, where buoyancy causes the spectral energy ''S'' to change with the −3 power of wavenumber ''k'':
<center>[[File:ams2001glos-Be28.gif
Industry:Weather
A vertical velocity scale ''w<sub>B</sub>'' for convective boundary layers, that is related to the buoyant driving force for convection and the depth ''z<sub>i</sub>'' of the mixed layer:
<center>[[File:ams2001glos-Be29.gif
Industry:Weather
