A type of rain gauge shield consisting of freely hanging, evenly spaced slats arranged circularly around the gauge. The advantage of this shield is that the slats do not easily accumulate snow, permitting its use on unattended gauges. See rain gauge shiel ...

A line drawn through geographical points having the same duration of sunshine (or other function of solar radiation) during a given interval of time.

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

Formation of a single water drop by the union of two or more colliding drops.

The distance that an observer can see vertically into a surface-based obscuring phenomenon such as fog, rain, or snow. The distance estimate must be based upon ceiling balloon ascensions or ceiling light projector measurements.

A sunshine recorder of the type in which the time scale is supplied by a chronograph. It consists of two bulbs, one of which is blackened, which communicate through a glass tube of small diameter. The tube is partially filled with mercury and contains two ...

Same as mirror nephoscope.

The value of the quantity measured, as indicated or otherwise provided by a measuring instrument.

A form of data transmission in which the bits of each character are sent one at a time along a single communication path. Compare to parallel data transmission.

Abbreviation for Instrument Flight Rules, but commonly used to refer to the weather and/or flight conditions to which these rules apply, i.e. low visibility.

An instrument used for measuring the specific gravity of a liquid.

See calorie.

See standard atmosphere.

The scientific study of the waters of the earth, especially with relation to the effects of precipitation and evaporation upon the occurrence and character of water in streams, lakes, and on or below the land surface. In terms of the hydrologic cycle, the ...

An instrument, dropped from high attitude and carried by a stable parachute. used to measure the vertical component of turbulence aloft.

Wind with a speed between 56 and 63 knots (64 and 72 mph); Beaufort scale number 11.

A unit of luminous intensity of a light source.

Clouds which cover between 6/10 and 9/10 of the sky. See Sky Terminology.

An instrument for measuring the extinction coefficient in water.

A series of Nansen-bottle water samples and associated temperature observations resulting from one release of a messenger.