A vector term which includes both wind speed and wind direction.

See hydrologic accounting.

An increase in the central pressure of a pressure system; opposite of a deepening. More commonly applied to a low rather than a high.

The state of the weather with respect to its effect upon the kindling and spreading of forest fires.

An estimate of the temperature of an incandescent body, determined by observing the wavelength at which it is emitting with peak intensity (its color) and using that wavelength in Wien's law.

A unit of power equal to one joule per second or 10' ergs per second.

An old nautical term for mercury barometer.

A general name for instruments which detect the presence of (but do not necessarily measure) small electrical charges by electrostatic means. Compare to electrometer.

The total area drained by a river and its tributaries. Same as river basin.

Electromagnetic radiation lying within the wavelength interval to which the human eye is sensitive, the spectral interval from approximately 0.4 to 0.7 microns (4000 to 7000 angstroms). Bounded on the short-wavelength end by ultraviolet radiation and on t ...

A measure of the attenuation due to scattering, of light as it traverses a medium containing scattering particles.

(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 ...

A radiosonde whose carrier wave is switched on and off in such a manner that the interval of time between the transmission of signals if a function of the magnitude of the meteorological elements being measured.

In thermodynamics, the integrating factor of the differential equation referred to as the first law of thermodynamics, In statistical mechanics, a measure of translational molecular kinetic energy (with three degrees of freedom). In general, the degree of ...

The gravity flow of water within soil.

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

The condition of the atmosphere when the amount of water vapor present is the maximum possible at the existing temperature.

In general, any object that reflects incident energy. Usually it is a device designed for specific reflection characteristics.

A unit of energy defined as the heat required to raise the temperature of one pound of water one degree Fahrenheit. It is equal to 252.1 calories or to 1055 joules.

A white disk 12" or more in diameter which is lowered into the sea to estimate transparency of the water. The depths are noted at which it first disappears when lowered and reappears when raised.