An approximation to the complete equations describing atmospheric motion in which only the terms most important for the growth and decay of synoptic scale extratropical weather systems (i.e., the large areas of high and low pressure seen on weather maps) ...

Same as ombrometer.

The ratio of the output of an instrument to the input value, i.e. a rain gauge with a sensitivity of 1 tip per 0.01"

The process by which one object becomes adhered to another by the binding action of ice.

The humidity transducinu element in a Diamond-Hinman radiosonde. Also called electrolytic strip.

Solar radiation of selected wavelengths.

Instrument for measuring the mean intensity of glo global solar radiation (direct and diffuse) near the earth's surface in a specified time interval.

An instrument, located at the surface observing station, which is used to record the data presented by a radiosonde aloft.

Turbulence encountered by aircraft when flying through air space devoid of clouds. Thermals and wind shear are the main causes.

An instrument for measuring snow hardness in terms of the resistance of snow to the pressure exerted by a disk attached to a spring-loaded rod, a gauge calibrated in pounds per square inch registers the amount of resistance. See Canadian hardness gauge.

A measure of the intensity of gusts given by the ratio of the total range of wind speed between gusts and the intermediate periods of lighter wind to the mean wind speed, averaged over both gusts and lulls.

An evaporation pan in which the evaporation is measured from water in a pan floating in a larger body of water.

General term for an instrument which records the vertical electric current in the atmosphere.

A hypothetical "body" whose surface absorbs no electromagnetic radiation of any wavelength. An idealization exactly opposite to that of the black body. In nature, no true white bodies are known. Moist white pigments exhibiting high reflectivity for visibl ...

An automatic, recording cloud height indicator.

Same as freezing point.

An instrument for determining the degree of polarization of light. See photopolarimeter.

A system of designating meteorological observing stations by number. established and administered by the World Meteorological Organization. Under this scheme, specified areas of the word are divided into "blocks" each bearing a two-number designator. Stat ...

A measure, proposed by Angstrom, of the precipitation effectiveness of a region.

A type of disk hardness-gauge, especially useful in relatively soft snow. See disk hardness gauge.