A type of rain gauge shield consisting of freely hanging, evenly spaced slats arranged circularly around the gauge. The advantage of this shield is that the slats do not easily accumulate snow, permitting its use on unattended gauges. See rain gauge shiel ...

The record made by a hygrograph.

A forecast of the expected stage or discharge at a specified time, or of the total volume of flow within a specified Interval of time, at one or more points along a stream.

The indicating part of an instrument. For example, the hand of a watch or the meniscus of a mercury column.

A wind (or component thereof) directed down the slope of an incline and caused by greater air density near the slope than at the same levels some distance horizontally from the slope. Also called drainage wind and sometimes called katabatic wind.

The total amount of water transferred to the atmosphere by evapotranspiration.

A unit of luminous intensity of a light source.

An absolute temperature scale with the ice point of pure water defined as 273.16 K. The size of the degree is the same as on the Celsius scale, and the zero point is absolute zero.

A liquid-in-metal thermometer in which mercury is enclosed in a steel envelope. The change in internal pressure caused by the temperature variation is measured by a Bourdon tube which is connected to the mercury by a capillary tube. This instrument is hig ...

The direction toward which the wind is blowing; with the wind.

See instrument error, observational error. random error, standard error, systematic error.

A unit of pressure equal to 10' dyne per cm-' (101 barye), 1000 millibars. 29.53 inches of mercury.

Emission or transfer of energy in the form of electromagnetic waves or particles.

Pertaining to the action or effect of the wind. Derived from the name of the Greek god of the winds, Aeolus.

An instrument for measuring the pressure of the atmosphere. The two principle types are aneroid and mercurial.

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 ...

A recording pressure-tube anemometer in which the wind scale of the float manometer has been made linear by the use of springs, i.e. Dines anemometer.

The energy of any type of electromagnetic radiation. Also called radiation.

A temperature scale on which the freezing point of water equals 32

(1) The initial component or the sensing element of a measuring system. For example, the receiver of a rain gauge is the funnel which captures the rain and the receiver of a thermoelectric thermometer is the measuring thermocouple. (2) An instrument used ...