Growth of a cloud or precipitation particle by the collision and union of a frozen particle with a super-cooled water drop.

An instrument which indicates the presence of dust particles in the atmosphere. Also spelled coniscope.

An instrument used for measuring geometric angles. See radio direction-finder.

Precipitation composed of balls or irregular lumps of ice with diameters between 5 and 50 mm.

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

An apparatus, used in studying soil temperatures, for measuring the total supply of heat during a given period.

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 ...

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

Overflowing by water of the normal confines of a stream or other body of water, or accumulation of water by drainage over areas which are not normally submerged.

Area of a computer or other device where various logic and control elements are interconnected. Often a printed circuit board into which other circuit boards plug at right angles.

Water vapor content of the air. See absolute humidity, dew point, mixing ratio, relative humidity, specific humidity.

A clock-driven instrument mounting which automatically and continuously points in the direction of the sun. It is used with a pyrheliometera,hen continuous direct solar radiation measurements are required.

That portion of the atmosphere which is above the lower troposphere. Generally applied to levels above 850 mb.

In general, solar radiation received at the earth's surface. Contracted from incoming solar radiation.

A radiosonde whose carrier wave is modulated by audio-frequency signals whose frequency is controlled by the sensing elements of the instrument.

An addition to a rawinsonde system which allows determination of the slant range to the radiosonde.

The amount of precipitation captured by a rain gauge.

An instrument used to indicate wind direction.

Eluding precise prediction, completely irregular.

Name sometimes given to a transmissometer.