A graphical representation of a frequency distribution. The range of the variable is divided into class intervals for which the frequency of occurrence is represented by a rectangular column. The height of the column is proportional to the frequency of ob ...

Difference between the temperatures of the dry-bulb and the wet-bulb thermometers of a psychrometer.

Same as rain-intensity gauge.

A modification of the dew cell used in radiosonde equipment.

An instrument which automatically records the voltage applied to it, as a function of time.

By international agreement, a period during which greatly increased observation of world-wide geophysical phenomena is undertaken through the co-operative effort of participating nations. July 1957-December 1958 was the first such year. However, precedent ...

The general term for anemometers operating on the principle that the heat transfer to air from an object at an elevated temperature is a function of the air speed. Examples are the hot-wire anemometer and the katathermometer.

A balloon-borne instrument for the simultaneous measurement and transmission of meteorological data. It includes transducers for the measurement of pressure, temperature, and humidity; a modulator for the conversion of the output of the transducers to a q ...

A device for measuring the height of tide. It may be simply a graduated staff in a sheltered location where visual observations can be made, or it may consist of an elaborate recording instrument (sometimes called a marigraph) making a continuous graphic ...

A hypothetical body which absorbs some constant fraction, between zero and one, of all electromagnetic radiation incident upon it, which fraction is the absorptivity and is independent of wavelength. Compare to black body, white body.

The unit of speed in the nautical system; one nautical mile per hour. It is equal to 1.1508 statute miles per hour or 0.5144 meters per second.

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

An instrument used to measure the water vapor content of the air.

See radiation shield.

A recording hair hygrometer.

The maximum positive and negative deviation observed in testing a device under specified conditions and by a specified procedure. It is usually measured as an inaccuracy and expressed as accuracy, typically in terms of the measured variable, percent of sp ...

A flower-like diagram indicating the relative frequencies of different wind directions for a given station and period of time.

A small pointer extending downward from the top of the cistern of a Fortin barometer. The level of the mercury in the cistern is adjusted so that it just comes in contact with the end of the pointer, thus setting the zero of the barometric scale.

The maximum difference in output for any given input (within the specified range) when the value is approached first with increasing, and then with decreasing, input signals. Caused by energy absorption in the elements of the measuring instrument. Usually ...

Same as balloon cover.