The point (physical and/or electrical) where two distinct data processing elements meet.

A self-recording psychrometer.

Of equal or constant pressure, with respect to either space or time.

Same as geostrophic wind level.

The physical exposure of an instrument. The effect of immediate environment upon the representativeness of the measurements obtained by meteorological instruments is considerable and not always correctable. The purpose of the instrument shelter is to prov ...

A hygrometer in which the rotation of the hygrometric element is a function of humidity.

A reversing thermometer which is encased in a strong glass outer shell that protects it against hydrostatic pressure. Compare to unprotected thermometer.

A synoptic code approved by the World Meteorological Organization in which the observable meteorological elements are encoded and transmitted in "words" of five numerical digits length. Often abbreviated synoptic code.

The total electromagnetic radiation emitted by the sun. About 99.9 percent of its energy output falls within the wavelength interval from 0. 15 microns to 4.0 microns, with peak intensity near 0.47 microns. About one-half of the total energy in the solar ...

Any conventional barometer fitted with an extended scale so that atmospheric pressure measurements may be made at both high and low altitudes.

The most common of the principal rainbow phenomena, which appears as an arc of about 42

The process of modifying some characteristic of a wave (the carrier) so that it varies in step with the instantaneous value of another wave (the modulating wave) in order to transmit a message. The modified characteristic may be frequency, phase, and/or a ...

Temperature assumed by an unsaturated air parcel when brought adiabatically to a standard pressure (1,000 mb).

A line drawn through all points on a map having the same amount of cloudiness.

See foehn.

A precipitation amount of less than 0.005 inches. Also, the record made by any self-registering instrument.

A thermometer based upon the principle that the velocity of a sound wave is a function of the temperature of the medium through which it passes. Sonic thermometers possess very short time-constants and eliminate radiation error.

A seasonal wind of persistent direction, characterized by a pronounced change in direction between seasons.

See constant-level balloon.

An instrument used to measure the water vapor content of the air. A type of hygrometer. It consists of a wet-bulb and a dry-bulb thermometer. See aspiration psychrometer, Assmann psychrometer. hygrodeik, sling psychrometer.