Same as wind sock.

Same as freezing point.

Same as balloon cover.

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

The inherent imprecision of a given process of measurement, the unpredictable component of repeated independent measurements of the same object under sensibly uniform conditions.

A numbering system using a base number of 2 and having only two digits: 0 and 1. The fundamental system of representing information with electrical pulses.

A unit of pressure equal to 10' dyne per cm-' (101 barye), 1000 millibars. 29.53 inches of mercury.

Abbreviation for mean sea level.

A form of psychrometer with wet-bulb and dry-bulb thermometers mounted on opposite sides of a specialty designed graph of the psychrometric tables. It is so arranged that the intersections of two curves determined by the wet-bulb and dry-bulb readings -yi ...

The atmospheric pressure at the level of the barometer. May or may not be the same as station pressure.

Any one of numerous devices for the measurement of either speed alone or of both direction and speed (set and drift) in flowing water.

Defect in the action of an aneroid barometer resulting in a sluggish adjustment of the index toward the correct reading when the barometer is subjected to a large and rapid change in pressure.

The gravity flow of water within soil.

A water-temperature thermometer provided with an insulated container around the bulb. It is lowered into the sea on a line until it has had time to reach the temperature of the surface water, then withdrawn and read. The insulated water surrounding the bu ...

Abbreviation for precipitation-evaporation quotient.

A recording anemoclinometer.

An instrument used to measure the water vapor content of the air.

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

See constant-level balloon.

A special type of radar target, usually a comer reflector, tied beneath a free balloon and designed to be an efficient reflector of radio energy.