A special type of radar target, usually a comer reflector, tied beneath a free balloon and designed to be an efficient reflector of radio energy.

The total infrared radiation emitted from the earth's surface. To be carefully distinguished from atmospheric radiation, effective terrestrial radiation, and insolation.

The cardinal points of the compass, i.e. north, south, east, west.

An instrument which measures evaporation by measuring the loss of water from a burette reservoir through a ceramic disc.

Name sometimes given to a transmissometer.

Wind with a speed between 4 and 27 knots (4 and 31 mph); Beaufort scale numbers 2 through 6.

See radiation shield.

The probability distribution of random errors, typically a normal distribution with a zero mean.

Same as evaporative power.

An instrument for the measurement of both solar and terrestrial radiation.

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.

A hygrometer which includes an arrangement for the time recording of atmospheric humidity.

An instrument for recording global solar radiation.

An anemometer in which the sensor rotation is transmitted to a mechanical counter which directly integrates the air movement past the sensor. Used to determine total air passage (wind run). Average wind speed can be calculated from the difference between ...

A rocket designed primarily for routine upper air observations in the lower 250,000 feet of the atmosphere, especially that portion inaccessible to balloons (above 100,000 feet).

A measure of the amount of "spin" (or rotation) in the atmosphere.

An ice coating with a consistency intermediate between glaze and rime.

Difference between the instantaneous wind velocity at a point and the mean wind velocity taken over a given time interval. Also called fluctuation velocity.

An instrument for determining the degree of polarization of light. See photopolarimeter.

See hydrologic accounting.