A flower-like diagram indicating the relative frequencies of different wind directions for a given station and period of time.

Rate of wind movement in distance per unit time.

A recording magnetometer.

A rainbow of angular radius of about 50

The total luminous flux received on a unit area of a given real or imaginary surface, expressed in such units as the foot-candle, lux, or phot.

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.

A rainbow formed by light rays which have been reflected from an extended water surface. Not to be confused with a reflected rainbow whose image may be seen in a still body of water. The center of a reflection rainbow is at the same elevation as the sun b ...

A chronograph used to make a time-record of certain measured meteorological elements. The most common type, the triple register, records wind direction and speed, duration of sunshine, and amount of rainfall (sensed respectively by a contact anemometer, M ...

A semiconductor which exhibits rapid and extremely large changes in resistance for relatively small changes in temperature.

General name for an instrument designed to measure the vertical component of the wind speed. See anemoclinometer.

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 ...

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

A sounding balloon which, when operationally inflated, resembles an inverted teardrop.

Small particle on which water vapor condenses.

An instrument for the measurement of the net flux of downward and upward total (solar and terrestrial) radiation through a horizontal surface.

A type of electrical thermometer consisting of two thermocouples which are series-connected with a potentiometer and a constant-temperature bath. One couple, called the reference junction, is placed in a constant-temperature bath, while the other is used ...

Navy Operational Global Atmospheric Prediction System. A global meteorological model operated by the Department of Defense.

A transducer for converting thermal energy directly into electrical energy. It is composed of pairs of thermocouples which are connected either in series or in parallel. Thermopiles are used in thermoelectric radiation instruments when the output of a sin ...

Having a specific relationship to a time base or clock. In synchronous communications, data characters are sent according to a timing signal which synchronizes the two communicating devices.

An instrument that shows changes in humidity.