Same as contact anemometer.

See instrument error, observational error. random error, standard error, systematic error.

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

An instrument used to measure the amount of dew formed on a given surface.

An instrument for the measurement of the rate of ice accretion on an unheated body.

Old snow that has become granular and compacted as a result of melting and refreezing.

A mercury barometer in which the lower mercury surface is larger in area than the upper surface. The basic construction of a cistern barometer is as follows: A glass tube one meter in length, sealed at one end is filled with mercury, and then inverted. Th ...

The ratio of the amount of electromagnetic radiation reflected by a body to the amount incipient upon it, commonly expressed as a percentage. The albedo is to be distinguished from the reflectivity, which refers to one specific wavelength.

Reduction of visibility by strong winds blowing across dry ground with little or no vegetation. Visibilities of 1/8 mile or less over a widespread area are criteria for a Blowing Dust Advisory.

Precipitation of very small, white opaque particles of ice, fairly flat or elongated, with diameters less than 1 mm. The solid equivalent of drizzle.

The distance or length of flow of the air past a point during a given interval of time.

The ceiling classification which is applied when the ceiling height is determined by timing the ascent and disappearance of a ceiling balloon or pilot balloon.

Operation mode of a communication circuit in which each end can transmit and receive, but not simultaneously.

An instrument for recording ocean waves. Most recorders are designed for recording wind waves, that is waves of periods up to about 25 seconds, but some are designed to record waves of longer periods such as tsunamis or tides.

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

The range of operating conditions of a device within which operating influences are negligible. The range is usually narrow. Reference operating conditions are the conditions under which reference performance is stated and the base from which the values o ...

That horizontal wind velocity at which the Coriolis acceleration exactly balances the horizontal pressure force. It is directed along contour lines or isobars.

An instrument for measuring the extinction coefficient in water.

A unit of power equal to one joule per second or 10' ergs per second.

The direction from which the wind is blowing, measured in points of the compass or in azimuth degrees.