Same as recording rain gauge.

The record of an aneroid barograph.

Wind with a speed between 41 and 47 knots (47 and 54 mph); Beaufort scale number 9.

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 ...

The temperature at which the liquid and solid forms of a substance may exist in equilibrium at a given pressure (usually one standard atmosphere). The true freezing point of water is known as the ice point.

An aneroid barograph designed to record atmospheric pressure variations of very small magnitude.

Radiation with wavelengths less than 4 microns.

Same as rain gauge.

The meteorological visual range, which can be estimated from the average extinction coefficient using the Koschmieder equation.

Instrument for measuring the depth of water from precipitation that is assumed to be distributed over a horizontal, impervious surface and not subject to evaporation.

A colorless and odorless gaseous element. The lightest and apparently the most abundant chemical element in the universe. However, it is found only in trace quantities in the observable portion of our atmosphere, only about 0.00005 percent by volume of dr ...

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

The amount of sky covered or concealed by clouds or obscuring phenomena. It is reported in tenths, so that 0.0 indicates a clear sky and 1.0 (or 10/10) indicates a completely covered sky. The following classifications are used in aviation weather observat ...

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.

General term for an instrument which records the vertical electric current in the atmosphere.

The process by which water in plants is transferred as water vapor to the atmosphere. Also, the amount of water so transferred.

A device which automatically records the water equivalent of snow on a given surface as a function of time. A small sample of a radioactive salt is placed in the ground in a shielded collimator which directs a beam of radioactive particles upwards. A Geig ...

Cathode Ray Tube. A display element, consisting of a vacuum tube and screen, used with computers.

Thermometer in which the difference in the rates of expansion with temperature of a liquid and its receptacle is used as a measure of the temperature. The liquid used may be ethyl alcohol, toluene, petroleum, or mercury.

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