The lowest level at which the wind becomes geostrophic in the theory of the Ekman spiral. Also called gradient wind level.

Same as luminous intensity.

A subtle, diumal component of the wind velocity leading to a diumal shift of the wind or turning of the wind with the sun, produced bv the east-to-west progression of daytime surface heating.

Radio Direction Finder.

Solar and terrestrial radiation directed upward (away From the earth's surface); outgoing radiation.

A measure of the attenuation due to scattering, of light as it traverses a medium containing scattering particles.

A type of cooling-power anemometer based upon the principle that the time constant of a thermometer is a function of its ventilation.

The energy of any type of electromagnetic radiation. Also called radiation.

A recording anemometer.

A system in which radar techniques are used to determine the range, elevation, and azimuth of a radar target carried a!oft by a radiosonde, so that wind data may be obtained along with the other meteorological data.

Precipitation falling from a cloud, usually in wisps or streaks, but evaporating before it reaches the ground.

A rain gauge which indicates but does not record the amount of precipitation captured.

Sir Napier Shaw's name for the approximate absolute temperature scale,

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 thermometer consisting of a clock mechanism the speed of which is a function of temperature.

See mote.

A general term for atmospheric water in any of its forms, i.e. clouds, fog, hail, ice crystals, rain.

A common unit used in measurement of atmospheric pressure. Defined as that pressure exerted by a one-inch column of mercury at standard gravity and a temperature of 0'C.

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

Complementary Metal-Oxide Semiconductor. A method of making silicon chips that results in low power consumption by the circuits.