The temperature to which a sample of air must be cooled, while the mixing ratio and barometric pressure remain constant, in order to attain saturation by water vapor. When this temperature is below O

A navigational aid used to facilitate the landing of an aircraft at an airport in instrument weather, i.e. low visibility.

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

An instrument resulting from the combination of a thermograph and a hygrograph and furnishing, on the same chart, simultaneous time recording of ambient temperature and humidity.

Same as geostrophic wind level.

Same as rain-intensity gauge.

Abbreviation for Instrument Flight Rules, but commonly used to refer to the weather and/or flight conditions to which these rules apply, i.e. low visibility.

A medium-sized instrument shelter. It is a white louvered box with a flat double to of and is mounted four feet above the ground on a four-legged stand.

An instrument which automatically records the measurement of two or more meteorological elements.

An instrument used to measure and record earthquake vibrations and other earth tremors.

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

An instrument, located at the surface observing station, which is used to record the data presented by a radiosonde aloft.

The water volume within a specified portion of a stream channel.

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

The envelope of air surrounding the earth and bound to it more or less permanently by virtue of the earth's gravitational attraction. The system whose chemical Properties. dynamic motions, and physical processes constitute the subject matter of meteorolog ...

In general, any object that reflects incident energy. Usually it is a device designed for specific reflection characteristics.

Closed, curved, flexible tube of elliptic cross section which is deformed, according to type, by variations of atmosphere spheric pressure or temperature and so provides a measurement of the particular parameter.

Operation mode of a communication circuit in which each end can simultaneously transmit and receive.

A sounding balloon which, when operationally inflated, resembles an inverted teardrop.

The length of fluid flow (gas or liquid) past a sensor required for the sensor to respond to 63.2% of a step change in speed. Expressed in feet or meters. For anemometers, this value is calculated from time constant times wind tunnel speed.