A small balloon, loaded with ballast and inflated so that it will explode at a predetermined altitude, which is attached to a larger balloon.

An instrument for the measurement of both solar and terrestrial radiation.

In a radiosonde observation, a level (other than a standard level) for which values of pressure, temperature, and humidity are reported because temperature and/or humidity data at that level is sufficiently important or unusual to warrant the attention of ...

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.

in United States weather observing practice, the highest "instantaneous" wind speed recorded at a station during a specified period, usually the 24-hour observation day. Therefore, a peak gust need not be a true gust of wind.

A subtle, diumal component of the wind velocity leading to a diumal shift of the wind or turning of the wind with the sun, produced bv the east-to-west progression of daytime surface heating.

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

Operation mode of a communication circuit in which each end can simultaneously transmit and receive.

The atmospheric pressure at mean sea level either directly measured by stations at sea level or empirically determined from the station pressure and temperature by stations not at sea level. Used as a common reference for analyses of surface pressure patt ...

A device which surrounds a rain gauge and acts to maintain horizontal flow in the vicinity of the funnel so that the catch will not be influenced by eddies generated near the gauge. See Alter shield, Nipher shield, Wild fence.

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

Determined by weighing a special type of wooden stick that has been exposed in the woods, its weight being proportional to its contained water.

A method of upper air observation consisting of an evaluation of the wind speed and direction, temperature, pressure, and humidity aloft by means of a balloon-borne radiosonde tracked by radar or a radio theodolite.

A wave resulting from the action of wind on a water surface.

Graduated fixed stake used in regions of abundant snowfall to facilitate the measurement of snow depth.

Any quantity, such as force velocity, or acceleration, which has both magnitude and direction at each point in space, as opposed to scalar which has magnitude only. Such a quantity may be represented geometrically by an arrow of length proportional to its ...

Operation mode of a communication circuit in which each end can transmit and receive, but not simultaneously.

Sustained winds greater than or equal to 40 mph or gust greater than or equal to 58 mph.

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

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