The correctable part of the inaccuracy of an instrument.

The portion of the precipitation on the land which ultimately reaches the streams. especially the water from rain or melted snow that flows over the surface.

A unit of luminance (or brightness) equal to 1/6 candles per square centimeter.

Same as photometer.

Same as aneroid barometer. Holostelic means wholly made of solids, while aneroid means devoid of liquid.

Name applied to a class of instruments which measure the liquid content of the atmosphere.

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

A recording weight barometer.

Abbreviation for precipitation effectiveness index.

The process in which incident radiation is retained by a substance. A further process always results from absorption.

See ceilometer.

A thermopile used in some types of radiation instruments. See solarimeter.

Precipitation falling from a cloud, usually in wisps or streaks, but evaporating before it reaches the ground.

A nephoscope in which the motion of the cloud is observed by its reflection in a mirror.

An absolute temperature scale with the degree of the Fahrenheit scale and the zero point of the Kelvin scale. The freezing point of water equals 491.69

Sustained winds greater than or equal to 40 mph or gust greater than or equal to 58 mph.

See wind vane.

Transistor-Transistor Logic.

Fine dust or salt particles dispersed through a portion of the atmosphere; a type of lithometer. The particles are so small they cannot be felt or seen with the naked eye. Many haze formations are caused by the presence of an abundance of condensation nuc ...

A curve showing the variation of temperature with height in the free air. See lapse rate.