- 行业: Weather
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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, ...
Any of a variety of processes or techniques to eliminate the effects of unwanted signals (clutter) in radar measurements. Clutter rejection most commonly refers to the filtering of the received signal to reject components that have specified phase or amplitude characteristics. In meteorological Doppler radar signal processing, for example, one approach to clutter rejection is to reject signals with Doppler velocities near zero, because stationary scattering objects induce no Doppler shift.
Industry:Weather
Any one of the properties or conditions of the atmosphere and ocean that together define the climate of a place (e.g., temperature, humidity, precipitation).
Industry:Weather
Any nonoccluded front, or portion thereof, that moves so that the colder air replaces the warmer air; that is, the leading edge of a relatively cold air mass. Compare cold type occlusion.
Industry:Weather
Any linear coordinates that are not Cartesian coordinates. If u, v, w are three functions of the Cartesian coordinates x, y, z and if at least one of these functions is not a linear combination of x, y, z, then u, v, w are curvilinear coordinates of the point the Cartesian coordinates of which are x, y, z provided that the Jacobian ∂(u,v,w)/∂(x,y,z) is not equal to zero. Any surface along which one of the three curvilinear coordinates is constant is called a coordinate surface; there are three families of such surfaces. Any line along which two of the three curvilinear coordinates are constant is called a coordinate line; there are three sets of such lines. Three distinct coordinate lines may be drawn through each point of space. The three straight lines each of which is tangent to one of the coordinate lines at a given point in space are called the local axes. If the local axes are everywhere mutually perpendicular, the curvilinear coordinates are said to be orthogonal or rectangular. Examples of frequently used curvilinear coordinates are polar coordinates and cylindrical coordinates. See also natural coordinates, spherical coordinates.
Industry:Weather
Any characteristic external crystalline form. For an ice crystal, may refer just to the ratio of the lengths of the crystal parallel to its c and a axes (at 90° to or parallel to the hexagonal basal plane), but usually it simply means the crystal shape, including dendritic, skeletal, prismatic, sectors, etc. The term is not applied to the internal crystal lattice. Slight variations in the growth rates of different crystal planes in a given crystal structure lead to quite different crystal habits. Such growth rate variations may result from variations in temperature and water vapor supersaturation of the environment in which the crystal grows.
Industry:Weather
Any development or strengthening of cyclonic circulation in the atmosphere; the opposite of cyclolysis. It is applied to the development of cyclonic circulation where previously it did not exist (commonly, the initial appearance of a low or trough) as well as to the intensification of existing cyclonic flow. While cyclogenesis usually occurs together with deepening (a decrease in atmospheric pressure), the two terms should not be used synonymously. Compare anticyclogenesis.
Industry:Weather
Any chemical compound containing chlorine (Cl), the 17th element in the periodic table. There are a number of chlorine-containing compounds found in the atmosphere, which are emitted from a variety of sources. Organic compounds containing chlorine are produced either via natural oceanic processes (e.g., methyl chloride) or for industrial purposes (e.g., chlorofluorocarbons). Some of these organic compounds are sufficiently long-lived to allow their transport to the stratosphere, where they are destroyed by photolysis. This process liberates chlorine atoms, which are active in the catalytic destruction of stratospheric ozone.
Industry:Weather
Annual tables of daily predictions of times and velocities of maximum flood currents and ebb currents and the times of slack water to be encountered in numerous coastal waterways.
Industry:Weather
Angle between the wind vector and an isobar, at any level. Such an angle is most conspicuous within the friction layer where the wind often has a component from high to low pressure.
Industry:Weather
An unpaid observer who maintains a meteorological station for the U. S. National Weather Service. Formerly termed a voluntary observer in the United States; the latter name is still used in the United Kingdom. The usual instruments furnished to such an observer are maximum and minimum thermometers and a nonrecording precipitation gauge.
Industry:Weather
