- Industry: 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, ...
The principle that the sky cover at any level is equal to the summation of the sky cover in the lowest layer, plus the additional sky cover in all successively higher layers up to and including the layer in question.
Industry:Weather
The procedure of calibrating a radar by measuring the power reflected by and returned to the radar from a conducting sphere of a known radar cross section. In principle, this method establishes the radar constant, including the effects of the antenna gain and any attenuation of the signal in the radar system between the antenna and the receiver, effects that are sometimes difficult to estimate by other means. In practice, the method is sometimes difficult to apply. The approach is usually to suspend the sphere beneath a tethered (sometimes free-floating) balloon. The problem is to keep the moving sphere at the center of the radar beam during the time required for a measurement of the returned power.
Industry:Weather
The portion of shortwave radiation illuminating a water surface that is reflected back to space. This reflection appears in visible imagery as a bright area on an otherwise dark water area when winds are light and the water surface is smooth. The rougher the water, the more diffuse the glint pattern.
Industry:Weather
The prevailing fundamental atmospheric circulation on a planetary scale that must exist in response to 1) radiation differences with latitude, 2) the rotation of the earth, and 3) the particular distribution of land and oceans; and that is required from the viewpoint of conservation of energy. Primary circulation and general circulation are sometimes taken synonymously. They may be distinguished, however, on the basis of approach; that is, primary circulation is the basic system of winds, of which the secondary and tertiary circulation are perturbations, while general circulation encompasses at least the secondary circulations. See macrometeorology.
Industry:Weather
The pressure that exists in a confined aquifer. Specifically, it is the elevation above a datum plus the pressure head.
Industry:Weather
The pressure that a component of a gaseous mixture would have if it alone occupied the same volume at the same temperature as the mixture. See Dalton's law.
Industry:Weather
The pressure of the water in a soil expressed relative to atmospheric pressure (gauge pressure).
Industry:Weather
The pressure (or force) on a body illuminated by electromagnetic radiation. By ordinary standards radiation pressure is extremely small. For example, the radiation pressure on an object exposed to intense sunlight is about 10<sup>11</sup> times smaller than sea level atmospheric pressure. But for small (comparable to or smaller than the wavelengths of visible and near-visible radiation) particles subjected to only the gravitational attraction of the sun and the repulsive radiation pressure of its radiation (e.g., cometary particles), radiation pressure is not negligible, which accounts for the curvature of the tails of comets.
Industry:Weather
The positive square root σ of the variance σ<sup>2</sup>. This is a measure of the scatter or spread in a series of observations.
Industry:Weather
