A temperature-sensing element which converts thermal energy directly into electrical energy. In its basic form it consists of two dissimilar metallic conductors connected in a closed loop. Each junction forms a thermocouple. If one thermocouple is maintai ...

To free something from the binding action of ice by warming it to a temperature above the melting point of ice. Also, a warm spell when ice and snow melt.

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.

The correction applied to an instrument to account for the effect of temperature upon its response characteristics.

An instrument for determining the direction of cloud motion. There are two basic designs of nephoscope, the directvision nephoscope and the mirror nephoscope.

The frequency of a carrier wave.

The size of the area comprising a watershed or river basin. Also called catchment area.

National Weather Service. Administered by the U.S. Department of Commerce.

The source of illumination for an antenna reflector. Also called antenna feed.

A measure of the intensity of gusts given by the ratio of the total range of wind speed between gusts and the intermediate periods of lighter wind to the mean wind speed, averaged over both gusts and lulls.

A counterclockwise change in wind direction. Backing winds with height are indicative of cold air advection (CAA).

A balloon-borne instrument for the simultaneous measurement and transmission of meteorological data. It includes transducers for the measurement of pressure, temperature, and humidity; a modulator for the conversion of the output of the transducers to a q ...

An instrument used to measure changes in the level of the water in an evaporation pan. The gauge is normally placed in a Stillwell and adjusted so that the point of the hook just breaks the water surface. The change in water level is read on the attached ...

An instrument for measuring the difference of the solar radiation falling on both sides of a horizontal surface from the whole hemisphere.

A unit of luminous intensity of a light source.

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.

Same as atmometer.

See feed.

In general, solar radiation received at the earth's surface. Contracted from incoming solar radiation.

Video Display Terminal. An input and display device which includes a keyboard and a screen and allows a human to communicate with a computer.