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

An instrument for measuring the difference between incoming and outgoing terrestrial radiation.

Same as balloon cover.

A balloon designed to float at a constant pressure level. This may be accomplished by a pressure valve which controls the release of ballast so as to maintain flight above a selected pressure level until the supply of ballast is exhausted. See Moby Dick b ...

The array of indicating marks and figure in relation to which the position of an index is observed, i.e. a scale plate on a recorder.

Atmospheric layer throughout which there is no change of temperature with height, i.e. a zero lapse rate.

Same as instrument shelter.

Same as ombrometer.

Radiation coming from the solid angle of the sun's disc, as opposed to diffuse sky radiation, effective terrestrial radiation, or radiation from any other source. Direct solar radiation is measured by pyrheliometers.

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

Apparatus from which the nature and time of precipitation may be determined.

In meteorology, a deflecting force acting on a body in motion and resulting from the earth's rotation. It deflects air currents to the right in the northern hemisphere and to the left in the southern hemisphere, thus having an effect on wind direction.

A type of electrical thermometer consisting of two thermocouples which are series-connected with a potentiometer and a constant-temperature bath. One couple, called the reference junction, is placed in a constant-temperature bath, while the other is used ...

Water vapor content of the air. See absolute humidity, dew point, mixing ratio, relative humidity, specific humidity.

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

In aviation terminology, route or terminal weather conditions of sufficiently low visibility to require the operation of aircraft under instrument flight rules.

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

Same as photometer.

Physical equipment used in data processing. Compare to firmware, software.

Wind with a speed between 28 and 55 knots (32 and 63 mph); Beaufort scale numbers 7 through 10.