See radar theodolite, radio direction-finder.

A contact anemometer connected to an electrical circuit which is so arranged that the average wind speed is indicated.

A temperature telemeter.

Electromagnetic radiation of shorter wavelength than visible radiation but longer than x-rays, between 0.02 and 0.4 micron (200 and 4000 angstrom).

The temperature at which a solid substance undergoes fusion, i.e. melts, changes from solid to liquid form. All substances have their characteristic melting points. For very pure substances the temperature range over which the process of fusion occurs is ...

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

An instrument for determining the direction of cloud motion. There are two basic designs of nephoscope, the directvision nephoscope and the mirror nephoscope.

NEXt Generation RADar. A NWS network of about 140 Doppler radars operating nationwide.

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

A thermometer with a muslin-covered bulb which is moistened. used to measure wet-bulb temperature.

Generic term for rapid variations in apparent position, brightness, or color of a distant luminous. object viewed through the atmosphere.

Same as instrument shelter.

The statement that the viscosity of air is independent of the density of air.

Precipitation caused by the ascent of moist air over an orographic barrier such as a Mountain range.

That horizontal wind velocity at which the Coriolis acceleration exactly balances the horizontal pressure force. It is directed along contour lines or isobars.

The change in the measured transducer output caused by changes in ambient temperature. Usually expressed a percentage of full scale.

A device, similar to a potometer, for measuring transpiration, consisting of a vessel containing soil in which one or more plants are rooted and sealed so that water can escape only by transpiration from the plant.

A conductor or system of conductors for radiating and/or receiving radio energy. Also called aerial.

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.

The correctable part of the inaccuracy of an instrument.