A systematic observational error due to the characteristics of the observer. The uncertainty in a reading made by an observer may be acertained by a statistical analysis of his or her readings.

A type of electrical thermometer consisting of two thermocouples which are series-connected with a potentiometer and a constant-temperature bath. One couple, called the reference junction, is placed in a constant-temperature bath, while the other is used ...

A local variation of the wind vector or any of its components in a given direction.

An instrument which measures the spectral distribution of the intensity of direct solar radiation.

A pyranometer developed by M. Robitzsch. Its design utilizes three bimetallic strips which are exposed horizontally at the center of a hemispherical glass bowl. The outer strips are white reflectors and the center strip is a blackened absorber. The bimeta ...

Same as wave pole.

Navy Operational Global Atmospheric Prediction System. A global meteorological model operated by the Department of Defense.

The addition of one or more redundant bits to information to verify its accuracy.

A device which automatically records the water equivalent of snow on a given surface as a function of time. A small sample of a radioactive salt is placed in the ground in a shielded collimator which directs a beam of radioactive particles upwards. A Geig ...

An instrument for measuring radiant energy. See actinometer, Dines radiometer, photometer, Tulipian radiometer.

Small particle on which water vapor condenses.

The probability distribution of random errors, typically a normal distribution with a zero mean.

A rainbow formed by light rays which have been reflected from an extended water surface. Not to be confused with a reflected rainbow whose image may be seen in a still body of water. The center of a reflection rainbow is at the same elevation as the sun b ...

A set of regulations set down by the U.S. Civil Aeronautics Board to govern the operational control of aircraft on instrument flight. The abbreviation of this term is seldom used to denote the rules themselves, but is in popular use to describe the weathe ...

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

The lowest value of a measured quality at which a sensor responds. Compare to tracking.

A semiconductor which exhibits rapid and extremely large changes in resistance for relatively small changes in temperature.

A transducer for converting thermal energy directly into electrical energy. It is composed of pairs of thermocouples which are connected either in series or in parallel. Thermopiles are used in thermoelectric radiation instruments when the output of a sin ...

A balloon-borne instrument for the simultaneous measurement and transmission of meteorological data. It includes transducers for the measurement of pressure, temperature, and humidity; a modulator for the conversion of the output of the transducers to a q ...

Same as humidity strip.