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

A hygrometer based upon the diffusion of water vapor through a porous membrane.

A temperature scale on which the freezing point of water equals 32

An instrument used for measuring the specific gravity of a liquid.

bucket rain gauge-A rain gauge where the precipitation collected by the receiver empties into one side of a chamber which is partioned transversely at its center and is balanced bistably upon a horizontal axis. When a predetermined amount of water has bee ...

A coating of ice, generally clear and smooth. formed by the freezing of supercooled water on a surface.

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 ...

The older name for the Celsius temperature scale. Officially abandoned by international agreement in 1948, but still in common use.

See constant-level balloon.

Federal Aviation Administration.

Same as ombrometer.

An ion counter of the aspiration condenser type, used for the measurement of the concentration and mobility of small ions in the atmosphere.

See stage.

The level at which ice crystals and snowflakes melt as they descend through the atmosphere.

Liquid water at temperatures colder than freezing.

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

A numbering system using a base number of 16 and including the ten decimal digits (0 to 9) along with six alpha digits (A to F). Thus. a digit is available to represent each of the possible values of a 4-bit binary digit.

A numbering system using a base number of 2 and having only two digits: 0 and 1. The fundamental system of representing information with electrical pulses.

Of or pertaining to rain.

The difference between the input quantity applied to a measuring instrument and the output quantity indicated by the instrument. The inaccuracy of an instrument is equal to the sum of its instrument error and its uncertainty.