A scale with the ice point at zero degrees and the boiling point of water at 80 degrees, with pressure of one atmosphere.

A line drawn through geographical points having the same pluvial index.

Physical equipment used in data processing. Compare to firmware, software.

A thermometer using transducing elements which deform with temperature. Examples are the bimetallic thermometer and the Bourdon tube type of thennometer.

Same as freezing point.

Read Only Memory. A memory that cannot be altered in normal use of a computer, Usually used to store information permanently, such as firmware programs.

A recording variometer.

The change in a performance characteristic caused by a change in a specified operating condition from reference operating condition, all other conditions being held within the limits of reference operating conditions.

A large body of air having similar horizontal temperature and moisture characteristics.

A systematic observational error due to the characteristics of the observer. The uncertainty in a reading made by an observer may be acertained by a statistical analysis of his or her readings.

See Koschmieder's law.

An instrument used to measure and record earthquake vibrations and other earth tremors.

The minimum temperature shown by a minimum thermometer exposed in an open situation with its bulb at the level of the tops of the grass blades of short turf.

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

film hygrometer element-An electrical hygrometer element constructed of a plastic strip coated with a film of carbon black dispersed in a hygroscopic binder. Variations in atmospheric moisture content vary the volume of the binder and thus change the resi ...

A device for measuring the height of tide. It may be simply a graduated staff in a sheltered location where visual observations can be made, or it may consist of an elaborate recording instrument (sometimes called a marigraph) making a continuous graphic ...

Temperature of equilibrium between the liquid and vapor phases of a substance at a given pressure.

An instrument that shows changes in humidity.

National Centers for Environmental Prediction. Central computer and communications facility of the National Weather Service; located in Washington, DC.

A radar which is used to obtain the azimuth elevation, and slant range of an airborne target.