The pressure exerted by the atmosphere as a consequence of gravitational attraction exerted upon the "column" of air lying directly above the point in question.

See hurricane beacon.

Federal Aviation Administration.

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

An instrument which automatically records the voltage applied to it, as a function of time.

General term for an instrument which records the vertical electric current in the atmosphere.

A medium-sized instrument shelter. It is a white louvered box with a flat double to of and is mounted four feet above the ground on a four-legged stand.

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

Very generally, any moving- stream of air. It has no particular technical connotation.

Abbreviation for precipitation-evaporation ratio.

Same as photometer.

Winds which, over a small area, differ from those which would be appropriate to the general pressure distribution.

The total of direct solar radiation and diffuse sky radiation received by a unit horizontal surface. Global radiation is measured by pyranometers.

A colorless and odorless gaseous element. The lightest and apparently the most abundant chemical element in the universe. However, it is found only in trace quantities in the observable portion of our atmosphere, only about 0.00005 percent by volume of dr ...

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 ...

A numbering system using a base number of 16 and including the ten decimal digits (0 to 9) along with six alpha digits (A to F). Thus. a digit is available to represent each of the possible values of a 4-bit binary digit.

Abbreviation for precipitation effectiveness index.

An apparatus, used in studying soil temperatures, for measuring the total supply of heat during a given period.

An instrument for measuring radiant energy. It consists of an ether differential thermometer with blackened bulbs. One of the bulbs is exposed to the unknown radiation and the other to a black body source whose temperature can be varied. Equality of radia ...

A measure of the intensity of gusts given by the ratio of the total range of wind speed between gusts and the intermediate periods of lighter wind to the mean wind speed, averaged over both gusts and lulls.