An instrument for measuring differences of electric potential.

An instrument used for measuring geometric angles. See radio direction-finder.

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

Temperature to which absolutely dry air would have to be brought in order for it to have the same density as moist air, considered at the same pressure.

See calorie.

Same as fogbow.

A wind blowing in a direction perpendicular to the course of a moving object.

The level at which ice crystals and snowflakes melt as they descend through the atmosphere.

The depth of water that would result from the melting of snow or ice, assuming measurement on a horizontal surface and no infiltration or evaporation.

A curve showing the variation of temperature with height in the free air. See lapse rate.

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

An instrument which measures the effective terrestrial radiation. See Angstrom pyrgeometer.

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

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 ...

Any device or instrument for measuring salinity, especially one based on electrical conductivity methods.

An aneroid barometer arranged so that the deflection of the aneroid capsule actuates a pen which graphs a record on a rotating drum. Sometimes called aneroidograph.

Solar radiation scattered by particles in the atmosphere.

An instrument for recording global solar radiation.

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

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