A wind vane used to obtain the horizontal and vertical components of the wind.

The wind speed and direction at various levels in the atmosphere above the level reached by surface weather observations.

National Centers for Environmental Prediction. Central computer and communications facility of the National Weather Service; located in Washington, DC.

Radiation with wavelengths greater than 4 microns. (In meteorology, same as infrared radiation.)

A standard unit of atmospheric pressure, defined as the pressure exerted by a 760 mm column of mercury at standard gravity (980.665 cm/sec2 ) at O

A small balloon whose ascent is followed by a theodolite in order to obtain data for the computation of winds aloft.

A water-temperature thermometer provided with an insulated container around the bulb. It is lowered into the sea on a line until it has had time to reach the temperature of the surface water, then withdrawn and read. The insulated water surrounding the bu ...

A type of cooling-power anemometer based upon the principle that the time constant of a thermometer is a function of its ventilation.

Any one of six gases, helium, neon, argon, krypton, xenon, and radon, all of whose shells of planetary electrons contain stable numbers of electrons such that the atoms are chemically inactive.

An instrument that automatically records pressure and temperature.

An instrument which measures the effective terrestrial radiation. See Angstrom pyrgeometer.

A device which converts energy from one form into another, i.e. an ac generator transducer which converts the mechanical motion of anemometer cups into an electrical signal.

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 ...

Of or pertaining to rain.

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

In a system of moist air, the ratio of the mass of water vapor to the total volume of the system. Usually expressed as grams per cubic meter (g/m3).

Same as dew-point hygrometer.

A general name for instruments which detect the presence of (but do not necessarily measure) small electrical charges by electrostatic means. Compare to electrometer.

The atmospheric pressure at the level of the barometer. May or may not be the same as station pressure.

The elevation of the water surface in a stream as measured by a river gauge with reference to some arbitrarily selected zero datum.