(1) The ratio of the speeds of a chemical reaction at two temperatures differing by 10

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.

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 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

The element directly responsive to the value of the measured variable.

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

The standard deviation (positive square-root of the variation) of the errors associated with physical measurements of an unknown quantity, or statistical estimates of an unknown parameter or of a random variable.

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 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.

in folklore, a name for fire.

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

A mercury barometer which measures atmospheric pressure by weighing the mercury in the column or cistern.

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

An instrument for the measurement of the radon content of the atmosphere.

Same as mercury barometer.

A precipitation gauge consisting of a receiver in the shape of a funnel which empties into a bucket mounted upon a weighing mechanism. The weight of the catch is recorded as inches of precipitation.

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

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

Balance of the water resources of a region, comparing precipitation and inflow with outflow, evaporation, and accumulation.