Radio Direction Finder.

An area of low atmospheric pressure which has a closed circulation that is cyclonic (counterclockwise in northern hemisphere and clockwise in southern hemisphere).

Clouds which cover between 6/10 and 9/10 of the sky. See Sky Terminology.

A general term to designate apparatus designed to observe the details of weather during thunderstorms.

A subtle, diumal component of the wind velocity leading to a diumal shift of the wind or turning of the wind with the sun, produced bv the east-to-west progression of daytime surface heating.

A Sunshine recorder of the type in which the time scale is supplied by the motion of the sun. The instrument, which is pointed at the celestial pole, consists of a hemispherical mirror mounted externally on the optical axis of a camera. The lens of the ca ...

An ice coating with a consistency intermediate between glaze and rime.

An instrument for collecting liquid water from the atmosphere.

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

Same as atmometer.

A small balloon used to determine the height of the cloud base. The height can be computed from the ascent velocity of the balloon and the time required for its disappearance into the cloud.

A unit of energy per unit area commonly employed in radiation theory. Equal to one gram-calorie per square centimeter.

An instrument for recording ocean waves. Most recorders are designed for recording wind waves, that is waves of periods up to about 25 seconds, but some are designed to record waves of longer periods such as tsunamis or tides.

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 process by which events in the real world are translated into machine-readable signals.

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 system of physical units based on the use of the centimeter, gram. and the second as elementary quantities of length. mass. and time.

The rising of cold water from the deeper areas of the ocean to the surface. This phenomena often occurs along the California coast during the spring and summer.

Same as constant-level balloon.

An instrument for photographing the corona and prominences of the sun at times other than at solar eclipse.