The gravity flow of water within soil.

Same as dropsonde.

A temperature telemeter.

The range of operating conditions within which a device is designed to operate and for which operating influences are stated. See operating conditions, reference operating conditions.

A wind blowing in a direction perpendicular to the course of a moving object.

A wooden enclosure about sixteen feet square and eight feet high with a precipitation gauge at its center. The function of the fence is to minimize eddies around the gauge and thus insure a catch that is representative of the actual rainfall or snowfall.

A type of cloud height indicator which uses a searchlight to project vertically a narrow beam of light onto the cloud base. The height of the cloud is determined using a clinometer, located at a known distance from the ceiling light, to measure the angle ...

Extended Binary Coded Decimal Interchange Code. A standard code used to represent data using 8 bits per character.

The transmission of data collected at a remote location over communications channels to a central station.

An estimate of the temperature of an incandescent body, determined by observing the wavelength at which it is emitting with peak intensity (its color) and using that wavelength in Wien's law.

A white disk 12" or more in diameter which is lowered into the sea to estimate transparency of the water. The depths are noted at which it first disappears when lowered and reappears when raised.

A curve showing the variation of temperature with height in the free air. See lapse rate.

The wind speed and direction at various levels in the atmosphere above the level reached by surface weather observations.

A tube designed to measure the rate of flow of fluids. It consists of a tube having a constriction or throat at its midsection. The difference between the pressure measured at the inlet and at the throat is a function of the fluid velocity. Compare to Pit ...

A rotation anemometer in which the axis of rotation is horizontal. The instrument has either flat vanes (as in the air meter) or helicoidal vanes (as in the propeller anemometer). The relation between wind speed and angular rotation is almost linear.

A conductor or system of conductors for radiating and/or receiving radio energy. Also called aerial.

That part of an audio-modulated radiosonde consisting of the baroswitch, the sensing elements, the reference elements, and the relay.

Routine broadcast of meteorological information for aircraft in flight.

Nested Grid Model generated every 12 hours by NCEP.

A common type of liquid-inglass thermometer, used, in meteorology, in psychrometers and as a maximum thermometer.