The downward flux of atmospheric radiation passing through a given level surface, usually taken as the earth's surface. This result of infrared (long-wave) absorption and reemission by the atmosphere is the principal factor in the greenhouse effect.

An aneroid barometer arranged so that the deflection of the aneroid capsule actuates a pen which graphs a record on a rotating drum. Sometimes called aneroidograph.

Strong winds concentrated within a narrow band in the atmosphere. The jet stream often "steers" surface features such as front and low pressure systems.

Turbulence encountered by aircraft when flying through air space devoid of clouds. Thermals and wind shear are the main causes.

An air-launched balloon designed to be released in the eye of a tropical cyclone, float within the eye at predetermined levels, and transmit radio signals for RDF positioning.

A device that combines several separate communications signals into one and outputs them on a single line.

In folklore, a name for rain.

A thermoelectric thermometer used for measuring air temperature. The name is derived from the fact that the reference thermocouple is placed in an insulated bottle.

A large plastic constant-level balloon for duration flying (in excess of 24 hours) at altitudes above 40,000 feet, used for the determination of wind fields and the measurement of upper atmospheric parameters.

A type of climatic diagram whose coordinates are some form of temperature vs. a form of humidity or precipitation.

The wind speed and direction at various levels in the atmosphere above the level reached by surface weather observations.

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

An instrument used for the measurement of the reflecting, power (the albedo) of a surface. A pyranometer adapted for the measurement of radiation reflected from the earth's surface is sometimes employed as an albedometer.

Same as dew-point hygrometer.

A recording anemometer.

Name sometimes used in place of pyranometer as a generic term.

(1) The ratio of the speeds of a chemical reaction at two temperatures differing by 10

Defect in the action of an aneroid barometer resulting in a sluggish adjustment of the index toward the correct reading when the barometer is subjected to a large and rapid change in pressure.

A unit of pressure which directly expresses the force exerted by the atmosphere. Equal to 1000 dynes/cm2 or 100 pascals.

A transducer for converting thermal energy directly into electrical energy. It is composed of pairs of thermocouples which are connected either in series or in parallel. Thermopiles are used in thermoelectric radiation instruments when the output of a sin ...