A definite portion of a stream channel, commonly taken between two gauging stations, but may be taken between any two specified points.

An instrument of the aspiration condenser type which measures the concentration and mobility of small ions.

Central Processing Unit. The part of a computer which controls and directs all functions.

Infrared radiation emitted by or being propagated through the atmosphere.

A reversing thermometer (for seawater temperature) which is not protected against hydrostatic pressure. The mercury bulb is therefore squeezed, and the amount of mercury broken off on reversal is a function of both temperature and of hydrostatic pressure.

The maximum difference in output for any given input (within the specified range) when the value is approached first with increasing, and then with decreasing, input signals. Caused by energy absorption in the elements of the measuring instrument. Usually ...

In folklore, a name for rain.

A relatively small-scale, upward moving current of air.

An instrument for the measurement of both solar and terrestrial radiation.

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

A colloquial term in western Australia for a squall, associated with thunder, on the northwest coast in summer.

The total of all deviations of a transducer's output from a specified straight line in a constant environment.

The record of an aneroid barograph.

The envelope of air surrounding the earth and bound to it more or less permanently by virtue of the earth's gravitational attraction. The system whose chemical Properties. dynamic motions, and physical processes constitute the subject matter of meteorolog ...

Temperature of equilibrium between the liquid and vapor phases of a substance at a given pressure.

Anemometer which measures wind speed by the speed of rotation of 3 or 4 hemispherical or conical cups, each fixed to the end of a horizontal arm projecting from a vertical axis. See condenser-discharge anemometer, contact anemometer. Compare to bridled-cu ...

An evaluation, according to set procedures, of those weather elements which are most important for aircraft operations. Always includes cloud height or vertical visibility, sky cover, visibility, obstructions to vision, certain atmospheric phenomena, and ...

A balloon designed to float at a constant pressure level. This may be accomplished by a pressure valve which controls the release of ballast so as to maintain flight above a selected pressure level until the supply of ballast is exhausted. See Moby Dick b ...

A recording variometer.

Same as freezing point.