See stage.

A photometric unit of illuminance or illumination equal to one lumen per square centimeter.

Frozen or partly frozen rain.

The nautical mile is closely related to the geographical mile which is defined as the length of one minute of arc on the earth's equator. By international agreement, the nautical mile is now defined as 1852 meters.

A recording anemoclinometer.

A device used to switch electrical current at a selectable setpoint temperature.

A polariscope consisting of a specially constructed double plate polarizer and a tourmaline plate analyzer. Polarized light passing through the instrument is indicated by the presence of parallel colored fringes, while unpolarized light results in a unifo ...

A type of directional antenna used on some types of radar and radio equipment consisting of an array of elemental, single- wire dipole antennas and reflectors.

Precipitation from a cumuliform cloud. Characterized by the suddenness of beginning and ending, by the rapid change in intensity, and usually by a rapid change in the condition of the sky. The solid or liquid water particles are usually bigger than the co ...

General term for an instrument which records the vertical electric current in the atmosphere.

The process by which one object becomes adhered to another by the binding action of ice.

Ice crystal deposits formed by sublimation (conversion of water vapor directly to ice) when temperature and dew point are below freezing.

General term for an instrument used to make direct measurements of visual range or measurements of the physical characteristics of the atmosphere which determine the visible range.

A conically shaped, copper rain gauge shield.

The rate of decrease of pressure per unit distance at a fixed time.

force wind-Wind with a speed above 64 knots (73 mph); Beaufort scale numbers 12 through 17.

A unit that represents one degree of deviation from a reference point in the mean daily outdoor temperature (usually 65

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

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 ...

A type of photoelectric photometer used to measure high-altitude winds on the assumption that stellar scintillation is caused by atmospheric inhomogeneities being carried along by wind near the tropopause level.