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

That part of snow melt that reaches stream channels as runoff.

A radiosonde equipped to measure temperature only.

A psychrometer in which the ventilation is provided by a suction fan.

An instrument which measures the instantaneous rate at which rain is falling on a given surface. Also called a rate-of-rainfall gauge.

An air-launched balloon designed to be released in the eye of a tropical cyclone, float within the eye at predetermined levels, and transmit radio signals for RDF positioning.

Winds from the four cardinal points of the compass; that is, north, east, south, and west winds.

A local variation of the wind vector or any of its components in a given direction.

Generally, the relative states of inflow, outflow, and storage of moisture over a given area of earth's surface.

A clay atmometer consisting of a hollow ceramic sphere through which evaporation occurs. Evaporation is measured by the loss of water from the reservoir which feeds the sphere.

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

A photoelectric spectrophotometer which is used in the determination of the ozone content of the atmosphere.

Cathode Ray Tube. A display element, consisting of a vacuum tube and screen, used with computers.

A mercury barometer designed for use aboard ship. The instrument is of the fixed-cistern type (see Kew barometer). The mercury tube is constructed with a wide bore for its upper portion and with a capillary bore for its lower portion. This is done to incr ...

An accumulation of granular ice tufts on the windward sides of exposed objects that is formed from supercooled fog or cloud and built out directly against the wind.

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

A rain gauge capable of measuring very small amounts of precipitation. Also called micropluviometer, trace recorder.

A systematic summary of the terms (inflow, outflow, and storage) of the storage equation as applied to the computation of soil-moisture changes, ground-water changes, etc. An evaluation of the hydrologic balance of an area. Also called basin accounting, w ...

A component of the wind (often using Cartesian coordinates. i.e. X and Y wind vectors). Also, an arrow representing wind velocity, drawn to point in the direction of the wind and with a length proportional to wind speed.

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 ...