See hurricane beacon.

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

See wind vane.

A small balloon used to determine the height of the cloud base. The height can be computed from the ascent velocity of the balloon and the time required for its disappearance into the cloud.

Electromagnetic radiation of very short wavelength. lying within the wavelength interval of 0.1 to 1.5 angstroms (between gamma rays and ultraviolet radiation). X-rays penetrate various thicknesses of all solids, and they act on photographic plates in the ...

A class of instruments employed to determine the electric potential at a point in the atmosphere, and ultimately the atmospheric electric field.

The closeness of agreement among a number of consecutive output values measuring the same input value under the same operating conditions, approaching from the same direction. Usually measured as nonrepeatability but expressed as repeatability, a percenta ...

A set of electrical conductors, often on a backplane, that carry data and power signals among the various components of a computer.

An anemometer which measures wind speed by means of the properties of wind-borne sound waves. It operates on the principle that the propagation velocity of a sound wave in a moving medium is equal to the velocity of sound with respect to the medium plus t ...

A polarimeter utilizing a Wollaston prism as a polarizer and a Nicol prism as an analyzer.

The inherent imprecision of a given process of measurement, the unpredictable component of repeated independent measurements of the same object under sensibly uniform conditions.

A hygrometer which includes an arrangement for the time recording of atmospheric humidity.

Same as Aeolian.

The ceiling classification which is applied when the ceiling height is determined by timing the ascent and disappearance of a ceiling balloon or pilot balloon.

In a system of moist air, the dimensionless ratio of the mass of water vapor to the total mass of the system.

A clock-driven device for recording the time of occurrence of an event or the time interval between the occurrence of events.

An aneroid barometer arranged so that the deflection of the aneroid capsule actuates a pen which graphs a record on a rotating drum. Sometimes called aneroidograph.

A point (or line) on a scale used for reference or comparison purposes. In calibration of meteorological thermometers, for example, the fiducial points are 100

A system of physical units based upon the use of the meter, the metric ton (106 grams), and the second as elementary quantities of length, mass, and time, respectively.

See gain.