A class of instruments employed to determine the electric potential at a point in the atmosphere, and ultimately the atmospheric electric field.

An instrument for measuring the extinction coefficient in water.

An instrument used for the measurement of the reflecting, power (the albedo) of a surface. A pyranometer adapted for the measurement of radiation reflected from the earth's surface is sometimes employed as an albedometer.

As used by the U.S. Army Corps of Engineers, the departure (in

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

An instrument for measuring the difference of the solar radiation falling on both sides of a horizontal surface from the whole hemisphere.

A vector term which includes both wind speed and wind direction.

An instrument for measuring the intensity of light or the relative intensity of a pair of lights. Also called an illuminometer. If the instrument is designed to measure the intensity of light as a function of wavelength, it is called a spectrophotometer. ...

A counterclockwise change in wind direction. Backing winds with height are indicative of cold air advection (CAA).

The line-of-sight distance between two objects.

The water portion of the earth as distinguished from the solid part, called the lithosphere, and from the gaseous outer envelope, called the atmosphere.

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.

A sudden brief increase in the speed of the wind, followed by a lull or slackening. Compare to peak gust.

The algebraic difference between the upper and lower limits of the measuring range of an instrument, i.e. a thermometer with a range of -35 to 50

A rain gauge or array of rain gauges designed to measure the inclination and direction of falling rain.

A thermometer using transducing elements which deform with temperature. Examples are the bimetallic thermometer and the Bourdon tube type of thennometer.

An estimate of the temperature of an incandescent body, determined by observing the wavelength at which it is emitting with peak intensity (its color) and using that wavelength in Wien's law.

The part of a measuring instrument which responds directly to changes in the environment.

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

A faintly-colored circular arc similar to a rainbow but formed on fog layers containing drops whose diameters are 100 microns or less. Also called mistbow, white rainbow.