The number of cycles per second between the limits of a frequency band.

The true freezing point of water. The temperature at which a mixture of air-saturated pure water and pure ice may exist in equilibrium at a pressure of one standard atmosphere.

An ion counter of the aspiration condenser type, used for the measurement of the concentration and mobility of small ions in the atmosphere.

A measure of the relative power, or of the relative values of two flux densities, especially of sound intensities and radar power densities. The decibel is derived from the less frequently used unit, the bel, named in honor of Alexander Graham Bell.

See Koschmieder's law.

A wind blowing in the same direction as the heading of a moving object. thus assisting the object's intended progress. The opposite of a head wind.

Very generally, any moving- stream of air. It has no particular technical connotation.

The amount of precipitation captured by a rain gauge.

An up slope wind due to local surface heating. Opposite of katabatic wind.

An automatic, recording cloud height indicator.

Old snow that has become granular and compacted as a result of melting and refreezing.

The height at which the maximum wind speed occurs, determined in a winds-aloft observation.

Instrument for measuring the depth to which the soil is frozen.

A small anemometer with flat vanes which indicates the number of linear feet or meters of air which have passed the instrument during its exposure.

See aneroid capsule.

A device for obtaining a continuous record of stage at a point on a stream. The most common recorders consist of a float-actuated pen which traces a record on a clock driven chart.

An ice coating with a consistency intermediate between glaze and rime.

Pertaining to measurements or devices in which the output varies continuously, i.e. voltage or rotation signals. Compare to digital.

A subtle, diumal component of the wind velocity leading to a diumal shift of the wind or turning of the wind with the sun, produced bv the east-to-west progression of daytime surface heating.

Operation mode of a communication circuit in which each end can transmit and receive, but not simultaneously.