A unit of energy per unit area commonly employed in radiation theory. Equal to one gram-calorie per square centimeter.

A hygrometer based upon the diffusion of water vapor through a porous membrane.

A thermometer which uses a transducing element whose element proper-ties are a function of its thermal state. Common meteorological examples of such thermometers are the resistance thermometer and the thermoelectric thermometer.

An Instrument used to determine dew point.

A type of cistern barometer in which the level of mercury in the cistern is adjusted to the zero point of the scale before each reading.

A recording hair hygrometer.

A precipitation amount of less than 0.005 inches. Also, the record made by any self-registering instrument.

A rain gauge which automatically records the amount of precipitation collected, as a function of time.

A method of winds aloft observation accomplished by tracking a balloon-borne radar target or radiosonde with either radar or a radio theodolite.

An optical instrument which consists of a sighting telescope mounted so that it is free to rotate around horizontal and vertical axes, with graduated scales so that the angles of rotation may be measured. Used to observe the motion of a pilot balloon.

The transducer of any hygrometer, i.e. that part of a hygrometer that quantitatively "senses" atmospheric water vapor.

A captive balloon used to maintain meteorological equipment aloft at approximately a constant height. The kytoon is streamlined and combines the aerodynamic properties of a balloon and a kite.

A water-temperature thermometer provided with an insulated container around the bulb. It is lowered into the sea on a line until it has had time to reach the temperature of the surface water, then withdrawn and read. The insulated water surrounding the bu ...

A fixed support for mounting maximum and minimum thermometers of the liquid-in-glass type. The support holds the thermometers at the correct operating attitude and also permits their rotation for resetting when desired.

check chamber-A chamber use to check the sensing elements of radiosonde equipment.

The probability distribution of random errors, typically a normal distribution with a zero mean.

In general, pertaining to or affording an overall view. In meteorology, this term has become somewhat specialized in referring to the use of meteorological data obtained simultaneously over a wide area for the purpose of obtaining a comprehensive and near ...

A tube designed to measure the rate of flow of fluids. It consists of a tube having a constriction or throat at its midsection. The difference between the pressure measured at the inlet and at the throat is a function of the fluid velocity. Compare to Pit ...

A hygrometer in which the rotation of the hygrometric element is a function of humidity.

A line drawn through points of equal humidity on given surface.