An instrument that shows changes in humidity.

A generic term for any machine that enables a human being to communicate with a computer.

The lowest value of a measured quality at which a sensor responds. Compare to tracking.

The record made by a hygrograph.

Any source of radiant energy, especially electromagnetic energy.

The distance or length of flow of the air past a point during a given interval of time.

A measure of the intensity of gusts given by the ratio of the total range of wind speed between gusts and the intermediate periods of lighter wind to the mean wind speed, averaged over both gusts and lulls.

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 ...

Same as river gauge.

A device which automatically records the water equivalent of snow on a given surface as a function of time. A small sample of a radioactive salt is placed in the ground in a shielded collimator which directs a beam of radioactive particles upwards. A Geig ...

See approximate absolute temperature scale, Celsius temperature scale, centigrade temperature scale, Fahrenheit temperature scale, Kelvin temperature scale, Rankine temperature scale, Reaumur temperature scale,

A device which surrounds a rain gauge and acts to maintain horizontal flow in the vicinity of the funnel so that the catch will not be influenced by eddies generated near the gauge. See Alter shield, Nipher shield, Wild fence.

A photometric unit of illuminance or illumination equal to one lumen per square centimeter.

Same as rain-intensity gauge.

A measurement of atmospheric conditions aloft, above the effective range of a surface weather observation. Elements evaluated include temperature, humidity, pressure, wind speed, and wind direction.

The difference between downward and upward (total) radiation; net flux of all radiation.

A sudden brief increase in the speed of the wind, followed by a lull or slackening. Compare to peak gust.

An evaluation of upper air temperature, pressure, and humidity from radio signals received from a balloon- borne radiosonde.

The difference between the solar radiation directed downward and upward; net flux of solar radiation.

Any one of six gases, helium, neon, argon, krypton, xenon, and radon, all of whose shells of planetary electrons contain stable numbers of electrons such that the atoms are chemically inactive.