The record or trace made by a microbarograph.

An aneroid barograph designed to record atmospheric pressure variations of very small magnitude.

Rain gauge which registers precipitation that is too light to be registered by ordinary recording of the depth of water from precipitation. Same as ombrometer.

A small, limited-capacity central processing unit contained entirely on one semiconductor chip.

A feeble oscillatory disturbance of the earth's crust, detectable only by very sensitive seismographs. Certain types of microseisms seem to be closely correlated with pressure disturbances. See microbarm.

A unit of pressure which directly expresses the force exerted by the atmosphere. Equal to 1000 dynes/cm2 or 100 pascals.

Thermometer used for measuring the lowest temperature attained during a given interval of time, for example, a day.

A nephoscope in which the motion of the cloud is observed by its reflection in a mirror.

A hydrometeor consisting of an aggregate of microscopic and more-or-less hygroscopic water droplets suspended in the atmosphere. It reduces visibility to a lesser extent than fog. The relative humidity of mist is often less than 95 percent.

Same as fogbow.

In a system of moist air, the dimensionless ratio of the mass of water vapor to the mass of dry air. For many purposes, the mixing ratio may be approximated by the specific humidity.

A large plastic constant-level balloon for duration flying (in excess of 24 hours) at altitudes above 40,000 feet, used for the determination of wind fields and the measurement of upper atmospheric parameters.

A device that allows a terminal or computer at one location to communicate with a terminal or computer at a distant location via wire or phone lines.

Wind with a speed between 11 and 16 knots (13 and 18 mph); Beaufort scale number 4.

Wind with a speed between 28 and 33 knots (32 and 38 mph); Beaufort scale number 7.

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 ...

A unit of mass numerically equal to the molecular weight of the substance. The gram-mote or gram-molecule is the mass in grams numerically equal to the molecular weight, i.e. a gram-mole of oxygen is 32 grams.

A thermopile used in some types of radiation instruments. See solarimeter.

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

A particular pattern of snow sampler having an internal diameter of 1.485 inches so that each inch of water in the sample weighs one ounce.