Turbulence encountered by aircraft when flying through air space devoid of clouds. Thermals and wind shear are the main causes.

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.

Wind with a speed between 17 and 21 knots (19 and 24 mph); Beaufort scale number 5.

A set of rules or conventions used to standardize data transfer between devices.

A unit of luminance (or brightness) equal to 1/6 candles per square centimeter.

The standard deviation (positive square-root of the variation) of the errors associated with physical measurements of an unknown quantity, or statistical estimates of an unknown parameter or of a random variable.

Any horizontal wind velocity tangent to the contour line of a constant pressure surface (or to the isobar of a geopotential surface) at the point in question.

The addition of one or more redundant bits to information to verify its accuracy.

A halo consisting of a faint white circle passing through the Sun and running parallel to the horizon for as much as 360

One of the radiation laws which states that the wavelength of maximum radiation intensity for a black body is inversely proportional to the absolute temperature of the radiating black body.

The component of the radiosonde which includes the modulating blocking oscillator and the radiofrequency carrier oscillator.

In folklore, a name for wind.

Wind with a speed below 1 knot (1 mph); Beaufort scale number 0.

A thin metal disc partially evacuated of air used to measure atmospheric pressure by measuring its expansion and contraction.

A graduated scale placed in a position so that the stage of a stream may be read directly from it. Staff gauges may be placed on bridge piers or pilings, etc., or placed on specially constructed supports.

Moisture contained in the soil above the water table, including water vapor which is present in the soil pores. In some cases this term refers strictly to the humidity contained in the root zone of plants.

Same as water year.

A device for measuring sea-surface waves. It consists of a weighted pole below which a disk is suspended at a depth sufficiently deep for the wave motion associated with deepwater waves to be negligible. The pole will then remain nearly as if anchored to ...

A method of upper air observation consisting of an evaluation of the wind speed and direction, temperature, pressure, and humidity aloft by means of a balloon-borne radiosonde tracked by radar or a radio theodolite.

The closeness of agreement among a number of consecutive output values measuring the same input value under the same operating conditions, approaching from the same direction. Usually measured as nonrepeatability but expressed as repeatability, a percenta ...