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

A general name for instruments which detect the presence of (but do not necessarily measure) small electrical charges by electrostatic means. Compare to electrometer.

The study of waters (including oceans, lakes, and rivers) embracing either: (a) their physical characteristics, from the standpoint of the oceanographer or limnologist; or (b) the elements affecting safe navigation, from the point of view of the mariner. ...

The rate of decrease of temperature with height when unsaturated air is lifted adiabatically (without exchange of heat with its surroundings). The decrease is due to expansion as the air is lifted to a lower pressure.

Solar radiation scattered by particles in the atmosphere.

Determined by weighing a special type of wooden stick that has been exposed in the woods, its weight being proportional to its contained water.

Phase Shift Keying. A form of phase modulation of a data signal performed by a modem for transmission over dedicated wire or phone lines.

The volume of liquid water evaporated per unit area in unit time. usually measured as the depth of liquid water lost per unit time from the whole area.

See standard atmosphere.

meter-An instrument for measuring the transmissivity of the atmosphere; a type of transmissometer. It consists of a constant- intensity collimated light source located at a suitable distance from a photoelectric cell. Variation in the turbidity of the atm ...

An anemometer utilizing the principle that the pitch of the aeolian tones generated by air moving past an obstacle is a function of the speed of the air. Largely a curiosity and has been put to no practical application in modem meteorology.

The center of an area of high pressure, usually accompanied by anticyclonic and outward wind flow. Also known as an anticyclone.

A very sensitive electrostatic electrometer for measuring small potential differences.

A large plastic constant-level balloon for duration flying at very high altitudes.

bucket rain gauge-A rain gauge where the precipitation collected by the receiver empties into one side of a chamber which is partioned transversely at its center and is balanced bistably upon a horizontal axis. When a predetermined amount of water has bee ...

A coating of ice, generally clear and smooth. formed by the freezing of supercooled water on a surface.

Central Processing Unit. The part of a computer which controls and directs all functions.

See gain.

A line drawn through geographical points having the same pluvial index.

An instrument for the measurement of both solar and terrestrial radiation.