The succession of stages through which water passes on the ground and in the atmosphere: evaporation from land or bodies of water, condensation to form clouds, precipitation, accumulation in the soil or in bodies of water, and re-evaporation.

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

An instrument for measuring angles of inclination. Used in conjunction with a ceiling light to measure cloud height at night.

The volume of water required to cover one acre to a depth of one foot: 43,560 cubic feet.

A direct-vision nephoscope constructed in the following manner: A grid-work of bars is mounted horizontally on the end of a vertical column and made free to rotate about the vertical axis. The observer rotates the grid and adjusts his or her position unti ...

Sir Napier Shaw's name for the approximate absolute temperature scale,

A wind blowing in the same direction as the heading of a moving object. thus assisting the object's intended progress. The opposite of a head wind.

A type of climatic diagram whose coordinates are some form of temperature vs. a form of humidity or precipitation.

A number of quantity defining a limit that errors will not exceed when a device is used under specified operating conditions. Accuracy rating can be expressed in a number of forms, i.e. in terms of the measured variable (+/- 1 C), percent of span (+/-0.5% ...

A device used to switch electrical current at a selectable setpoint temperature.

An instrument which measures the intensity of radiation by determining the amount of chemical change( or fluorescence produced by that radiation.

Abbreviation for radio frequency.

A type of pressure-tube anemometer, named after the inventor.

A measure of the intensity of gusts given by the ratio of the total range of wind speed between gusts and the intermediate periods of lighter wind to the mean wind speed, averaged over both gusts and lulls.

General name for an instrument which measures the evaporation rate of water into the atmosphere. See clay atmometer, evaporation pan, evapotranspirometer, Livingston sphere, Piche evaporimeter, radio atmometer.

Overflowing by water of the normal confines of a stream or other body of water, or accumulation of water by drainage over areas which are not normally submerged.

A line of equal or constant temperature.

The writing component of a recording instrument.

An instrument, dropped from high attitude and carried by a stable parachute. used to measure the vertical component of turbulence aloft.

An instrument for measuring the difference between incoming and outgoing terrestrial radiation.