The process by which one object becomes adhered to another by the binding action of ice.

The ratios, to the mean wind speed, of the average magnitudes of the component fluctuations of the wind along three mutually perpendicular axes.

An instrument which measures the intensity of radiation by determining the amount of chemical change( or fluorescence produced by that radiation.

A fabric cone attached to a metal ring and used to indicate wind direction. often at airfields.

Meteorological information issued by a watch office concerning the occurrence or forecast of weather phenomena which may affect the safety of aircraft operations.

An instrument developed by K. Angstrom for measuring the effective terrestrial radiation. It consists of four manganin strips, of which two are blackened and two are polished. The blackened strips are allowed to radiate to the atmosphere while the polishe ...

A hydrometeor consisting of a visible aggregate of minute water and/or ice particles in the atmosphere above the earth's surface. Cloud differs from fog only in that the latter is, by definition, in contact with the earth's surface.

Wind with a speed between 28 and 33 knots (32 and 38 mph); Beaufort scale number 7.

Temperarure at which a liquid solidifies under any given set of conditions. It may or may not be the same as the melting point or the more rigidly defined true freezing point or (for water) ice point.

A small balloon used to determine the height of the cloud base. The height can be computed from the ascent velocity of the balloon and the time required for its disappearance into the cloud.

One of several constant-pressure levels in the atmosphere for which a complete evaluation of data derived from upper air observations is required.

A common unit used in measurement of atmospheric pressure. Defined as that pressure exerted by a one-inch column of mercury at standard gravity and a temperature of 0'C.

A basic equation in night visual range theory, relating the illuminance of a point source of light to distance and the transmissivity of the atmosphere.

The energy of any type of electromagnetic radiation. Also called radiation.

The succession of stages through which water passes on the ground and in the atmosphere: evaporation from land or bodies of water, condensation to form clouds, precipitation, accumulation in the soil or in bodies of water, and re-evaporation.

A box-like structure designed to protect certain meteorological instruments from exposure to direct sunlight, precipitation, and condensation, while at the same time providing adequate ventilation. Instrument shelters are painted white, have louvered side ...

A recording anemoclinometer.

A temperature telemeter.

A wooden enclosure about sixteen feet square and eight feet high with a precipitation gauge at its center. The function of the fence is to minimize eddies around the gauge and thus insure a catch that is representative of the actual rainfall or snowfall.

Video Display Terminal. An input and display device which includes a keyboard and a screen and allows a human to communicate with a computer.