The gravity flow of water within soil.

The lowest level at which the wind becomes geostrophic in the theory of the Ekman spiral. Also called gradient wind level.

One of the radiation laws which states that the wavelength of maximum radiation intensity for a black body is inversely proportional to the absolute temperature of the radiating black body.

A buoyant balloon kept from rising freely by means of a line secured to a point on the ground, as opposed to a free balloon. See kytoon.

Any twelve-month period, usually selected to begin and end during a relative dry season. Used a basis for processing streamflow and other hydrologic data. The period from October 1 to September 30 is widely used in the U.S.

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.

A form of data transmission in which the bits of each character are sent one at a time along a single communication path. Compare to parallel data transmission.

An instrument for the measurement of the net flux of downward and upward total (solar and terrestrial) radiation through a horizontal surface.

The study of waters (including oceans, lakes, and rivers) embracing either: (a) their physical characteristics, from the standpoint of the oceanographer or limnologist; or (b) the elements affecting safe navigation, from the point of view of the mariner. ...

The transducer's output when the maximum sensed value is applied to the transducer's input. For example, the F.S. output of a 4-20 mA transmitter is 20 mA, whereas its span is only 16mA.

The total electromagnetic radiation emitted by the sun. About 99.9 percent of its energy output falls within the wavelength interval from 0. 15 microns to 4.0 microns, with peak intensity near 0.47 microns. About one-half of the total energy in the solar ...

In general, solar radiation received at the earth's surface. Contracted from incoming solar radiation.

The value of atmospheric pressure to which the scale of a pressure altimeter is set so as to indicate airport elevation. The altimeter setting is included as part of an aviation weather observation.

Sustained winds greater than or equal to 40 mph or gust greater than or equal to 58 mph.

A device for measuring the river stage. Also called stream gauge.

An instrument for collecting liquid water from the atmosphere.

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

A rain gauge which indicates but does not record the amount of precipitation captured.

The process in which incident radiation is retained by a substance. A further process always results from absorption.

The ratio of the existing amount of water vapor in the air at a given temperature to the maximum amount that could exist at that temperature. Usually expressed in percent.