- Industry: 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, ...
A technique used to study the relationship between two time series, where one series records the occurrence or nonoccurrence of a discrete event of particular interest and the other consists of data for a hypothetically related variable. Relationships are established or rejected by comparison of variable behavior before or after the occurrence of like events. As a meteorological example, the method might be used to examine the influence of sunspot maxima (discrete events) on cloud cover (the variable).
Industry:Weather
A technique used in numerical modeling, particularly ocean modeling, in which predicted variables are slowly changed toward prescribed values. The prescribed values are typically based on observations. An arbitrary time constant determines the degree to which the predicted variables can deviate from the prescribed values.
Industry:Weather
A systematic observational error due to the characteristics of the observer. The uncertainty in a reading made by an observer may be ascertained by a statistical analysis of his readings.
Industry:Weather
A system that evolves in time according to probabilistic equations, that is, the behavior of the system is determined by one or more time-dependent random variables.
Industry:Weather
A system or flow that evolves slowly in time compared to the rotation period of the earth, has a length scale of the deformation radius or larger, and undergoes only limited vertical excursions. Formally, the quasigeostrophic system of equations is derived from an expansion of terms in powers of the Rossby number, which is presumed small.
Industry:Weather
A system of mixed Eulerian and Lagrangian coordinates. At least one coordinate of each fluid parcel must therefore be unvarying with time. Such a system takes advantage of the fact that in many atmospheric models there is one property (but not three properties) conserved in the motion. The most frequently used system of this type is the (''x'', ''y'', θ) system under adiabatic motions, where ''x'' and ''y'' are Cartesian coordinates, and θ the potential temperature. If water vapor in all phases is admitted to the system, wet-bulb potential temperature or a similar conservative temperature may be used.
Industry:Weather
A system of differential equations with solutions that contain a rapidly damping component (as would describe the displacement of a stiff spring when stretched and then released). Such systems are used to describe rapid photochemical reactions that take place in the upper atmosphere. Special numerical techniques are often required to solve stiff systems in order to maintain stability of the computation.
Industry:Weather
A system in which the flow characteristics, such as depth of flow or mean velocity, at any given point, do not change with time.
Industry:Weather
A surface synoptic station other than a principal synoptic station.
Industry:Weather
A surface weather observation, made at periodic times (usually at three-hourly and six-hourly intervals specified by the World Meteorological Organization), of sky cover, state of the sky, cloud height, atmospheric pressure reduced to sea level, temperature, dewpoint, wind speed and direction, amount of precipitation, hydrometeors and lithometeors, and special phenomena that prevail at the time of the observation or have been observed since the previous specified observation. Compare aviation weather observation.
Industry:Weather
