Name sometimes given to a transmissometer.

A device that allows a terminal or computer at one location to communicate with a terminal or computer at a distant location via wire or phone lines.

Same as marine rainbow.

A point (or line) on a scale used for reference or comparison purposes. In calibration of meteorological thermometers, for example, the fiducial points are 100

The ratio of the existing amount of water vapor in the air at a given temperature to the maximum amount that could exist at that temperature. Usually expressed in percent.

The volume of liquid water evaporated per unit area in unit time. usually measured as the depth of liquid water lost per unit time from the whole area.

Same as instrument shelter.

The mass density of a parcel of air expressed in units of mass per volume.

Hygrometer in which the dew (frost) point is determined by observing the temperature of an artificially cooled surface at the moment at which dew (frost) first appears on it.

A graphical representation of a frequency distribution. The range of the variable is divided into class intervals for which the frequency of occurrence is represented by a rectangular column. The height of the column is proportional to the frequency of ob ...

An instrument used for the determination of the electrical conductivity of the atmosphere.

A remote indicator for wind speed and direction used in conjunction with a contact anemometer and a wind vane. The indicator consists of a center light, connected to the contact anemometer, surrounded by eight equally spaced lights which are individually ...

See sea-water thermometer, reversing thermometer.

Difference between the instantaneous wind velocity at a point and the mean wind velocity taken over a given time interval. Also called fluctuation velocity.

National Weather Service. Administered by the U.S. Department of Commerce.

A record obtained from a meteorograph. A chart in which meteorological variables are plotted against time.

An instrument for photographing the corona and prominences of the sun at times other than at solar eclipse.

Balance of the water resources of a region, comparing precipitation and inflow with outflow, evaporation, and accumulation.

A hygrometer which includes an arrangement for the time recording of atmospheric humidity.

For a given location, a measure of the long-range effectiveness of precipitation in promoting plant growth. Also called precipitation-evaporation index.