The volume of liquid water evaporated per unit area in unit time. usually measured as the depth of liquid water lost per unit time from the whole area.

A standard interface between a computer input/output port and a peripheral device. Signal properties including time duration, voltage. and current, are specified by the Electronic Industries Association.

A small, limited-capacity central processing unit contained entirely on one semiconductor chip.

A protocol similar to RS232 which makes use of differential transmission to provide high speed data transmission over significantly longer distances.

The water portion of the earth as distinguished from the solid part, called the lithosphere, and from the gaseous outer envelope, called the atmosphere.

Determined by weighing a special type of wooden stick that has been exposed in the woods, its weight being proportional to its contained water.

Thermometer in which the difference in the rates of expansion with temperature of a liquid and its receptacle is used as a measure of the temperature. The liquid used may be ethyl alcohol, toluene, petroleum, or mercury.

A hypothetical body which absorbs some constant fraction, between zero and one, of all electromagnetic radiation incident upon it, which fraction is the absorptivity and is independent of wavelength. Compare to black body, white body.

An anemometer which measures wind speed in terms of the drag which the wind exerts on a solid body. See bridled-cup anemometer, normal-plate anemometer, pendulum anemometer.

Same as ombrometer.

A high-altitude sounding system consisting of a small solid- propellant research rocket carried aloft by a large plastic balloon. The rocket is fired near the maximum altitude of the balloon flight.

Same as an upper air observation, but commonly used to refer to a single complete radiosonde observation.

A measure of luminous flux remaining in a light beam after it has passed through a specified distance of the atmosphere.

A particular pattern of snow sampler having an internal diameter of 1.485 inches so that each inch of water in the sample weighs one ounce.

See calorie.

Electromagnetic radiation lying in the wavelength interval between 0.8 micron and I millimeter. At the lower limit of this interval, the infrared radiation spectrum is bounded by visible radiation, while on its upper limit it is bounded by microwave radia ...

A measure of the intrinsic luminous intensity emitted by a source in a given direction. Luminance is a measure only of light. The comparable term for electromagnetic radiation in general is radiance.

General term for any device that measures precipitation: principally a rain gauge or snow gauge.

Rate of flow of water past a point in a stream, expressed as volume per unit time, i.e. cubic feet per second.

Thermometer used for measuring the lowest temperature attained during a given interval of time, for example, a day.