A unit of distance equal to 5280 feet. It is sometimes referred to as a land mile.

The transducer of any hygrometer, i.e. that part of a hygrometer that quantitatively "senses" atmospheric water vapor.

Generally, an instrument designed to measure or estimate the blueness of the sky. See Linke-scale.

Emission or transfer of energy in the form of electromagnetic waves or particles.

NEXt Generation RADar. A NWS network of about 140 Doppler radars operating nationwide.

An instrument for photographing the corona and prominences of the sun at times other than at solar eclipse.

A c.g.s. (centimeter-gram-second) unit of mass. Originally defined as the mass of 1 cubic centimeter of water at 4

Instrument for measuring the depth of water from precipitation that is assumed to be distributed over a horizontal, impervious surface and not subject to evaporation.

Any meteorological instrument, such as a radiosonde, in which the recording apparatus is located at some distance from the measuring apparatus.

A general term for instruments designed to measure the amount of cloudiness.

See aneroid capsule.

For a given location, a measure of the long-range effectiveness of precipitation in promoting plant growth. Also called precipitation-evaporation index.

force wind-Wind with a speed above 64 knots (73 mph); Beaufort scale numbers 12 through 17.

A cup anemometer with its shaft mechanically coupled to a magneto.

A thermometer based upon the principle that the velocity of a sound wave is a function of the temperature of the medium through which it passes. Sonic thermometers possess very short time-constants and eliminate radiation error.

Same as dropsonde.

A large plastic constant-level balloon for duration flying at very high altitudes.

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 ...

A clay atmometer consisting of a hollow ceramic sphere through which evaporation occurs. Evaporation is measured by the loss of water from the reservoir which feeds the sphere.

A clock-driven instrument mounting which automatically and continuously points in the direction of the sun. It is used with a pyrheliometera,hen continuous direct solar radiation measurements are required.