Precipitation caused by the ascent of moist air over an orographic barrier such as a Mountain range.

See radar theodolite, radio direction-finder.

A halo consisting of a faint white circle passing through the Sun and running parallel to the horizon for as much as 360

Same as marine rainbow.

Generic term for rapid variations in apparent position, brightness, or color of a distant luminous. object viewed through the atmosphere.

An instrument for the measurement of the rate of ice accretion on an unheated body.

Upwarddirected solar radiation, reflected by the earth's surface and the atmosphere.

An instrument used to reveal but not necessarily measure the presence of an electrical quantity. It is used to display the output of a sensing element after suitable amplification and modification. Sometimes called display.

A refraction phenomenon similar to a parahelion, but occurring generally at a distance of 120

A thermometer which uses a transducing element whose element proper-ties are a function of its thermal state. Common meteorological examples of such thermometers are the resistance thermometer and the thermoelectric thermometer.

A conductor or system of conductors for radiating and/or receiving radio energy. Also called aerial.

The change in the measured transducer output caused by changes in ambient temperature. Usually expressed a percentage of full scale.

Sir Napier Shaw's name for the approximate absolute temperature scale,

A wooden enclosure about sixteen feet square and eight feet high with a precipitation gauge at its center. The function of the fence is to minimize eddies around the gauge and thus insure a catch that is representative of the actual rainfall or snowfall.

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 state of the atmosphere, mainly with respect to its effects upon life and human activities. As distinguished from climate, weather consists of the short-term (minutes to months) variations of the atmosphere.

The array of indicating marks and figure in relation to which the position of an index is observed, i.e. a scale plate on a recorder.

An instrument used for the determination of the electrical conductivity of the atmosphere.

Not a linear function of the relevant variables.

The upper surface of a column of liquid.