Same as luminous intensity.

See stage.

Same as dew-point hygrometer.

Solar radiation of selected wavelengths.

The portion of the precipitation on the land which ultimately reaches the streams. especially the water from rain or melted snow that flows over the surface.

Physical equipment used in data processing. Compare to firmware, software.

Generally, an instrument designed to measure or estimate the blueness of the sky. See Linke-scale.

A rainbow formed by light rays which have been reflected from an extended water surface. Not to be confused with a reflected rainbow whose image may be seen in a still body of water. The center of a reflection rainbow is at the same elevation as the sun b ...

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.

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

A class of rain gauge in which the level of the collected rain water is measured by the position of a float resting on the surface of the water.

An instrument which indicates the presence of precipitation. The ombroscope consists of a heated, water-sensitive surface which indicates by mechanical or electrical techniques the occurrence of precipitation.

In a system of moist air, the dimensionless ratio of the mass of water vapor to the total mass of the system.

A graphical representation of a frequency distribution. The range of the variable is divided into class intervals for which the frequency of occurrence is represented by a rectangular column. The height of the column is proportional to the frequency of ob ...

Video Display Terminal. An input and display device which includes a keyboard and a screen and allows a human to communicate with a computer.

Abbreviation for visual flight rules, but commonly used to refer to the relatively favorable weather and/or flight conditions to which these rules apply.

Snow gauge composed of a metal cylinder, closed at one end, used to obtain a sample of snow from which the water is measured after melting.

A type of cistern barometer in which the level of mercury in the cistern is adjusted to the zero point of the scale before each reading.

An instrument for measuring the ultraviolet in solar and sky radiation.

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