Same as humidity strip.

Water vapor content of the air. See absolute humidity, dew point, mixing ratio, relative humidity, specific humidity.

A small balloon, loaded with ballast and inflated so that it will explode at a predetermined altitude, which is attached to a larger balloon.

Same as rain gauge.

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.

Hygrometer in which the dew (frost) point is determined by observing the temperature of an artificially cooled surface at the moment at which dew (frost) first appears on it.

Same as ombrometer.

That portion of the record of a microbarograph between any two (or a specified small number) of successive crossings of the average pressure level (in the same direction). Analogous to microseism.

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

A recording siphon barometer.

A captive balloon used to maintain meteorological equipment aloft at approximately a constant height. The kytoon is streamlined and combines the aerodynamic properties of a balloon and a kite.

A measurement of atmospheric conditions aloft, above the effective range of a surface weather observation. Elements evaluated include temperature, humidity, pressure, wind speed, and wind direction.

A modification of the dew cell used in radiosonde equipment.

An instrument used to measure and record earthquake vibrations and other earth tremors.

An instrument for measuring the ultraviolet in solar and sky radiation.

Determined by weighing a special type of wooden stick that has been exposed in the woods, its weight being proportional to its contained water.

Moisture contained in the soil above the water table, including water vapor which is present in the soil pores. In some cases this term refers strictly to the humidity contained in the root zone of plants.

See river basin.

Growth of a cloud or precipitation particle by the collision and union of a frozen particle with a super-cooled water drop.

Generally, the relative states of inflow, outflow, and storage of moisture over a given area of earth's surface.