The height ascribed to the lowest layer of clouds or obscuring phenomena when it is reported as broken, overcast, or obscuration and not classified as "thin" or "partial." The ceiling is termed unlimited when these conditions are not satisfied. ...

A small anemometer with flat vanes which indicates the number of linear feet or meters of air which have passed the instrument during its exposure.

An instrument for collecting liquid water from the atmosphere.

Very generally, any moving- stream of air. It has no particular technical connotation.

Operation mode of a communication circuit in which each end can transmit and receive, but not simultaneously.

The pressure exerted by the atmosphere as a consequence of gravitational attraction exerted upon the "column" of air lying directly above the point in question.

A thermometer whose sensitive element has been made to resemble a black body by covering it with lamp black. The thermometer is placed in an evacuated transparent chamber which is maintained at a constant temperature. The instrument responds to insolation ...

A small balloon, loaded with ballast and inflated so that it will explode at a predetermined altitude, which is attached to a larger balloon.

In folklore, a name for rain.

In the direction from which the wind is blowing.

A wind vane used to obtain the horizontal and vertical components of the wind.

A clockwise change in wind direction. Veering winds with height are indicative of warm air advection (WAA).

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

See aneroid capsule.

American Standard Code for Information Interchange. A standard code used to represent data using 8 bits (7 data bits and I parity bit) per character.

The general term for anemometers operating on the principle that the heat transfer to air from an object at an elevated temperature is a function of the air speed. Examples are the hot-wire anemometer and the katathermometer.

An instrument which indicates the presence of precipitation. The ombroscope consists of a heated, water-sensitive surface which indicates by mechanical or electrical techniques the occurrence of precipitation.

A hygrometer using goldbeater's skin as the sensitive element. Variations of the physical dimensions of the skin caused by its hygroscopic character indicate relative humidity. (Note: Goldbeater's skin is the prepared outside membrane of the large intesti ...

A general term for instruments designed to measure the speed or force of the wind.

For a given cloud or cloud laver. the lowest level in the atmosphere at which the air contains a perceptible quantity of cloud particles.