Generally, an instrument designed to measure or estimate the blueness of the sky. See Linke-scale.

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

An atmospheric sounding instrument which is supported by a captive balloon and used to obtain temperature and humidity data from the ground level to a height of a few thousand feet. The data is telemetered to the ground through a wire cable.

The cardinal points of the compass, i.e. north, south, east, west.

An instrument consisting of a series of graduated cylinders possessing selective collection efficiencies. It is used for the measurement of quantities relating to the size distribution of cloud droplets.

The state of the weather with respect to its effect upon the kindling and spreading of forest fires.

Precipitation of very small, white opaque particles of ice, fairly flat or elongated, with diameters less than 1 mm. The solid equivalent of drizzle.

In physics, any process in which the flux density (or power, amplitude, intensity, illuminance, etc.) of a "parallel beam" of energy decreases with increasing distance from the source. Attenuation is always due to the action of the transmitting medium its ...

A recording weight barometer.

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

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.

A protective coating applied to circuits.

Lacking a relationship to a time base or clock. In asynchronous communications, individual data characters are sent at an arbitrary rate.

A sunshine recorder of the type in which the time scale is supplied by the motion of the sun. It consists of two opaque metal semi-cylinders mounted with their curved surfaces facing each other. Each of the semi-cylinders has a short narrow slit in its fl ...

A type of climatic diagram whose coordinates are some form of temperature vs. a form of humidity or precipitation.

In nautical terminology, a contraction for "weather glass" (a mercury barometer).

Abbreviation for the pressure, temperature, and humidity data obtained by a radiosonde observation.

A thermometer used in aircraft which automatically corrects for adiabatic and frictional temperature rises by imparting a rotary motion to the air passing the thermal sensing element.

A small, limited-capacity central processing unit contained entirely on one semiconductor chip.

Lowest altitude in the atmosphere over a given location at which the air temperature is 0