Downward scattered and reflected solar radiation, coming from the whole hemisphere with the exception of the solid angle of the sun's disc on a surface perpendicular to the axis of this cone.

A hygrometer using goldbeater's skin as the sensitive element. Variations of the physical dimensions of the skin caused by its hygroscopic character indicate relative humidity. (Note: Goldbeater's skin is the prepared outside membrane of the large intesti ...

That temperature at which, in a specified latitude, the reading of a particular barometer requires no temperature or latitude correction.

A fixed support for mounting maximum and minimum thermometers of the liquid-in-glass type. The support holds the thermometers at the correct operating attitude and also permits their rotation for resetting when desired.

Dihydrogen oxide, molecular formula H2O.

In radiometry, a measure of the intrinsic radiant intensity emitted by a radiator in a given direction.

See gain.

A photometer which measures the intensity of radiation as a function of the frequency (or wavelength) of the radiation.

An effect noted primarily in wet snow conditions when snow clings to the sides of a precipitation gauge and gradually accumulates until the gauge orifice is capped with accumulated snow. This effect can be minimized by using large collectors, and wind scr ...

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

National Centers for Environmental Prediction. Central computer and communications facility of the National Weather Service; located in Washington, DC.

An ice coating with a consistency intermediate between glaze and rime.

(1) The initial component or the sensing element of a measuring system. For example, the receiver of a rain gauge is the funnel which captures the rain and the receiver of a thermoelectric thermometer is the measuring thermocouple. (2) An instrument used ...

Having a specific relationship to a time base or clock. In synchronous communications, data characters are sent according to a timing signal which synchronizes the two communicating devices.

General term for any device that measures precipitation: principally a rain gauge or snow gauge.

A thermometer designed for use in measuring the temperature of sea water. One form consists of a mercury-in-glass thermometer protected by a perforated metal case. Another form consists of a mercury-in-glass thermometer surrounded by a metal case which fo ...

Same as river gauge.

Infrared radiation emitted by or being propagated through the atmosphere.

Similar to the spectroheliograph, but used for visual instead of photographic purposes.

A radiosonde which transmits the indication of the meteorological sensing elements in the form of a code consisting of combinations of dots and dashes.