A component of the wind (often using Cartesian coordinates. i.e. X and Y wind vectors). Also, an arrow representing wind velocity, drawn to point in the direction of the wind and with a length proportional to wind speed.

The actual time during which physical events take place.

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 total infrared radiation emitted from the earth's surface. To be carefully distinguished from atmospheric radiation, effective terrestrial radiation, and insolation.

Either of two colored luminous spots that appear at points 22

in folklore, a name for fire.

An instrument which measures combined direct solar radiation and diffuse sky radiation. See pyrheliometer, Robitzsch actinograph. solarimeter. See also albedometer.

The maximum distance, usually horizontally, at which a given object or light source is just visible under particular conditions of transmittance and background luminance.

To free something from the binding action of ice by warming it to a temperature above the melting point of ice. Also, a warm spell when ice and snow melt.

The difference between the outgoing infrared terrestrial radiation of the earth's surface and the downcoming infrared counterradiation from the atmosphere.

A weakly colored lunar halo identical in form and optical origin to the solar parhelion.

Any one of a family of circular arcs consisting of concentric colored bands, arranged from red on the inside to blue on the outside, which may be seen on a "sheet" of water drops (rain, fog, spray). The most common of the many possible is the primary rain ...

A metallic element of atomic weight 200.6 1, unique (for metals) in that it remains liquid under all but very extreme temperatures.

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.

The measuring, transmitting, receiving, and indicating apparatus for obtaining the value of a quantity at a distance.

Wind with a speed between 22 and 27 knots (25 and 31 mph); Beaufort scale number 6.

An apparatus, used in studying soil temperatures, for measuring the total supply of heat during a given period.

A form of data transmission in which the bits of each character are all sent simultaneously, resulting in extremely fast communication but requiring a communication path for each bit. Compare to serial data transmission.

Rate of wind movement in distance per unit time.

The depth below which the ground is saturated with water. No water table exists if the ground water is confined by an overlying impermeable stratum, as in the case of artesian ground water.