A magnetometer of the electromagnetic type which is used to measure the horizontal intensity of the earth's magnetic field.

The total amount of water transferred to the atmosphere by evapotranspiration.

A polarimeter utilizing a Wollaston prism as a polarizer and a Nicol prism as an analyzer.

A photometer which measures the intensity of radiation as a function of the frequency (or wavelength) of the radiation.

A radiosonde which is dropped by parachute from an aircraft for the purpose of obtaining soundings of the atmosphere below.

The lowest value of a measured quality at which a sensor meets its accuracy specification.

The atmospheric pressure computed using station elevation as the reference datum level. Station pressure is usually the base value from which sea level pressure and altimeter setting are determined.

A line of equal or constant temperature.

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.

An effect noted primarily in wet snow conditions when snow clings to the sides of a precipitation gauge and gradually accumulates until the gauge orifice is capped with accumulated snow. This effect can be minimized by using large collectors, and wind scr ...

Amount of solar radiation incident, per unit area and time, on a surface which is perpendicular to the radiation and is situated at the outer limit of the atmosphere, the earth being at its mean distance from the sun. It equals approximately 2.00 ly/ min ...

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 humidity transducinu element in a Diamond-Hinman radiosonde. Also called electrolytic strip.

A graphical representation of stage or discharge at a point on a stream as a function of time.

A measure of long-term precipitation effectiveness. The ratio of the normal annual rainfall to the normal annual evaporation.

Same as precipitation- effectiveness index.

A systematic summary of the terms (inflow, outflow, and storage) of the storage equation as applied to the computation of soil-moisture changes, ground-water changes, etc. An evaluation of the hydrologic balance of an area. Also called basin accounting, w ...

A warm, dry wind on the lee side of a mountain range, the warmth and dryness due to adiabatic compression upon descent.

See constant-level balloon.

A buoyant balloon rising freely in the atmosphere, as opposed to a captive balloon.