Same as mirror nephoscope.

See evaporation pan.

An empirical curve relating stream discharge or stage at a point on a stream to discharge or stage at one or more upstream points and, possibly. to other parameters. Also called stage relation.

Same as wind sock.

Same as contact anemometer.

A graphical aid used in fire weather forecasting to calculate the degree of forest-fire danger (or burning index). Commonly in the form of a circular slide rule, the firedanger meter relates numerical indices of (a) the seasonal stage of foliage, (b) the ...

A general term for instruments designed to measure the amount of cloudiness.

A device for measuring the frequency of occurrence of atmospherics whose intensity is greater than a predetermined level.

The standard deviation of a sufficiently large number of measurements of the same quantity by the same instrument or method. The non-correctable part of the inaccuracy of an instrument, it represents the limit of measurement precision. The uncertainty of ...

A hypothetical "body" whose surface absorbs no electromagnetic radiation of any wavelength. An idealization exactly opposite to that of the black body. In nature, no true white bodies are known. Moist white pigments exhibiting high reflectivity for visibl ...

Part of a computer word that has meaning in itself, often, a byte.

Difference between the instantaneous wind velocity at a point and the mean wind velocity taken over a given time interval. Also called fluctuation velocity.

A decrease in the central pressure of a pressure system. Usually applied to a low rather than to a high.

Any one of numerous devices for the measurement of either speed alone or of both direction and speed (set and drift) in flowing water.

A rain gauge capable of measuring very small amounts of precipitation. Also called micropluviometer, trace recorder.

A thermoelectric thermometer used for measuring air temperature. The name is derived from the fact that the reference thermocouple is placed in an insulated bottle.

General term for an instrument used to make direct measurements of visual range or measurements of the physical characteristics of the atmosphere which determine the visible range.

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 ...

Video Display Terminal. An input and display device which includes a keyboard and a screen and allows a human to communicate with a computer.

A radiosonde which transmits the indication of the meteorological sensing elements in the form of a code consisting of combinations of dots and dashes.