A sunshine recorder of the type in which the time scale is supplied by the motion of the sun. It consists essentially of a spherical lens which bums an image of the sun upon a specialty prepared card.

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

A buoyant balloon rising freely in the atmosphere, as opposed to a captive balloon.

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

See Koschmieder's law.

A system of physical units based on the use of the centimeter, gram. and the second as elementary quantities of length. mass. and time.

Same as luminous intensity.

A standard interface between a computer input/output port and a peripheral device. Signal properties including time duration, voltage. and current, are specified by the Electronic Industries Association.

A standard unit of atmospheric pressure, defined as the pressure exerted by a 760 mm column of mercury at standard gravity (980.665 cm/sec2 ) at O

An instrument that automatically records pressure and temperature.

An instrument used to measure changes in the level of the water in an evaporation pan. The gauge is normally placed in a Stillwell and adjusted so that the point of the hook just breaks the water surface. The change in water level is read on the attached ...

pattern barometer-Mercurial barometer with a fixed scale and cistern and which therefore requires only one adjustment before each reading.

A graphical representation of stage or discharge at a point on a stream as a function of time.

A synoptic code approved by the World Meteorological Organization in which the observable meteorological elements are encoded and transmitted in "words" of five numerical digits length. Often abbreviated synoptic code.

Abbreviation for precipitation effectiveness index.

Same as river gauge.

The visibility along an identified runway, determined from a specified point on the runway with the observer facing in the same direction as a pilot using the runway. Compare to runway visible range.

Precipitation from a cumuliform cloud. Characterized by the suddenness of beginning and ending, by the rapid change in intensity, and usually by a rapid change in the condition of the sky. The solid or liquid water particles are usually bigger than the co ...

A type of modulation in which the frequency of a continuous radio carrier wave is varied in accordance with the properties of a second (modulating) wave.

A instrument designed to study small fluctuations of some quantity. The microbarograph is an example of a recording pressure variometer.