A rainbow of angular radius of about 50

A temperature scale based on absolute zero. Same as Kelvin temperature scale.

A set of rules or conventions used to standardize data transfer between devices.

Apparatus in which radar techniques are used to determine the range, elevation, and azimuth of a balloonborne target, to computer upper-air wind data. It is a type of rawin system.

An instrument for determining the degree of polarization of light. See photopolarimeter.

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

A unit of illuminance or illumination equal to one lumen per foot'. This is the illuminance provided by a light source of one candle at a distance of one foot.

The writing component of a recording instrument.

A sounding balloon which, when operationally inflated, resembles an inverted teardrop.

The state of the atmosphere, mainly with respect to its effects upon life and human activities. As distinguished from climate, weather consists of the short-term (minutes to months) variations of the atmosphere.

Transistor-Transistor Logic.

A unit of luminance or brightness equal to 1/d candles per foot'.

A counterclockwise change in wind direction. Backing winds with height are indicative of cold air advection (CAA).

A small balloon used to determine the height of the cloud base. The height can be computed from the ascent velocity of the balloon and the time required for its disappearance into the cloud.

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 component of a radiosonde consisting of a series of alternate electrically conducting and insulating strips. As these are scanned by a contact the radiosonde transmits temperature and humidity signals alternately. The contact may be a baroswitch as in t ...

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

The measurement and computation of wind speeds and directions at various levels above the surface of the earth. Methods include pilot balloon observations, rabals, rawin or rawinsonde observations, radar tracking, or acoustic sounding.

The maximum deviation of any points from a straight line drawn as a "best fit" through the calibration points of an instrument with a linear response curve. Usually expressed as a percentage of full- scale range.

Wind with a speed between 48 and 55 knots (55 and 63 mph), Beaufort scale number 10.