| Section S | S index | 451-459 of 1376 terms |
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site characterization1. A general term applied to the investigation activities at a specific location that examine natural phenomena and human-induced conditions important to the resolution of environmental, safety, and water-resource issues. 2. The program of exploration and research, both in the laboratory and in the field, undertaken to establish the geologic conditions and the ranges of the geologic parameters of a particular site relevant to the program. It includes borings, surface excavations, excavation of exploratory shafts, limited subsurface lateral excavations and borings, and in situ testing at depths needed to determine the suitability of the site for a geologic repository, but does not include preliminary borings and geophysical testing needed to decide whether site characterization should be undertaken.
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site of stationThe location of a meteorological station from the point of view of geography, orientation, and position of shelter and various instruments to include latitude, longitude, and elevation.
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Six's thermometerA combination maximum thermometer and minimum thermometer. The tube is shaped in the form of a “U” having a bulb at either end. One bulb is filled with a clear liquid that expands or contracts with temperature variation, forcing before it a short column of mercury having iron indices at either end. The indices remain at the extreme positions reached by the mercury column, thus indicating the maximum and minimum temperatures. The indices can be reset with the aid of a magnet.
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size parameterThe ratio of the size of a spherical scattering particle to the wavelength of the radiation being scattered, that is, α = πd/λ, where d is the diameter of the particle, and λ is the wavelength of the incident radiation. Mie theory describes the general process of extinction, scattering, and absorption of spherical particles as a function of the size parameter and refractive index. For α < ≈0.1, the Rayleigh scattering approximation becomes valid, whereas for α > ≈100, geometrical optics becomes valid.
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skavlerA Norwegian word generally equivalent to sastrugi.
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skillA statistical evaluation of the accuracy of forecasts or the effectiveness of detection techniques. Several simple formulations are commonly used in meteorology. The skill score (SS) is useful for evaluating predictions of temperatures, pressures, or the numerical values of other parameters. It compares a forecaster's root-mean-squared or mean-absolute prediction errors, Ef, over a period of time, with those of a reference technique, Erefr, such as forecasts based entirely on climatology or persistence, which involve no analysis of synoptic weather conditions:  If SS > 0, the forecaster or technique is deemed to possess some skill compared to the reference technique. For binary, yes/no kinds of forecasts or detection techniques, the probability of detection (POD), false alarm rate (FAR), and critical success index (CSI) may be useful evaluators. For example, if A is the number of forecasts that rain would occur when it subsequently did occur (forecast = yes, observation = yes), B is the number of forecasts of no rain when rain occurred (no, yes), and C is the number of forecasts of rain when rain did not occur (yes, no), then    For perfect forecasting or detection, POD = CSI =1.0 and FAR = 0.0. POD and FAR scores should be presented as a pair.
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