Generally, a measure of the departure of the mean daily temperature from a given standard, one degree day for each degree (

Same as evaporative power.

A measure of the attenuation due to scattering, of light as it traverses a medium containing scattering particles.

Same as atmometer.

A type of pressure-tube anemometer, named after the inventor.

Name sometimes given to a transmissometer.

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

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

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.

The upward force produced by the gas in a balloon. It is equal to the free lift plus the weight of the balloon and the attached equipment.

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.

See stage.

Same as aneroid barometer. Holostelic means wholly made of solids, while aneroid means devoid of liquid.

A special type of radar target, usually a comer reflector, tied beneath a free balloon and designed to be an efficient reflector of radio energy.

A type of cyanometer. an instrument used to measure the blueness of the sky. The Linke-scale is simply a set of eight cards of different standardized shades of blue. They are evenly numbered 2 to 26. The odd numbers are used by the observer if he or she j ...

A type of atmometer. It is a pan used in the measurement of the evaporation of water into the atmosphere. The NWS Class A pan is a cylindrical container 48 inches in diameter and 10 inches deep.

A colloquial term in western Australia for a squall, associated with thunder, on the northwest coast in summer.

Interational thermometric scale on which the freezing point of water equals 0

A pyrheliometer of the thermoelectric type. Radiation is allowed to fall on two concentric silver rings, the outer covered with magnesium oxide and the inner covered with lamp black. A system of thermocouples (thermopile) is used to measure the temperatur ...

The element directly responsive to the value of the measured variable.