Wind with a speed below 1 knot (1 mph); Beaufort scale number 0.

A fixed-length group of bits representing the large data element handled as a unit by a computer. Word length is determined by the capacity of the CPU registers.

A pressure-operated switching device used in a radiosonde. In operation, the expansion of an aneroid capsule causes an electrical contact to scan a radiosonde commutator composed of conductors separated by insulators.

An instrument designed to measure quantities of heat. Sometimes used in meteorology to measure solar radiation.

A recording anemoclinometer.

A unit of signaling speed representing the number of code elements sent per second; often, bits per second.

An atmospheric sounding instrument which is supported by a captive balloon and used to obtain temperature and humidity data from the ground level to a height of a few thousand feet. The data is telemetered to the ground through a wire cable.

The group of bits which a computer processes as a unit; often, 8 bits.

A basic equation in night visual range theory, relating the illuminance of a point source of light to distance and the transmissivity of the atmosphere.

A river gauge in which a weight suspended on a wire is lowered to the water surface from a bridge or other overhead structure to measure the distance from a point of known elevation to the water surface.

An instrument for measuring the pressure of the atmosphere. The two principle types are aneroid and mercurial.

The portion of the strearnflow during any month or year derived from precipitation in previous months or years.

See river basin.

A unit of pressure equal to 10' dyne per cm-' (101 barye), 1000 millibars. 29.53 inches of mercury.

Same as luminous intensity.

An instrument which determines the altitude of an object with respect to a fixed level. There are two general types of altimeters: (a) the pressure altimeter, which gives an approximate measure of altitude from a pressure measurement and an assumed standa ...

Area of a computer or other device where various logic and control elements are interconnected. Often a printed circuit board into which other circuit boards plug at right angles.

An instrument which indicates the presence of dust particles in the atmosphere. Also spelled coniscope.

A medium-sized instrument shelter. It is a white louvered box with a flat double to of and is mounted four feet above the ground on a four-legged stand.

The record of a barograph.