A series of Nansen-bottle water samples and associated temperature observations resulting from one release of a messenger.

General name for a type of instrument which measures the inclination of the wind to the horizontal plane. See bivane.

The maximum distance, usually horizontally, at which a given object or light source is just visible under particular conditions of transmittance and background luminance.

A barometer which measures atmospheric pressure using one or a series of aneroid capsules. Also called holosteric barometer.

A sunshine recorder of the type in which the time scale is supplied by the motion of the sun. It consists of two opaque metal semi-cylinders mounted with their curved surfaces facing each other. Each of the semi-cylinders has a short narrow slit in its fl ...

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

The height at which the maximum wind speed occurs, determined in a winds-aloft observation.

National Weather Service. Administered by the U.S. Department of Commerce.

Negative Vorticity Advection.

A severe weather condition characterized by low temperatures and strong winds bearing a great amount of snow, either falling or picked up from the ground.

A thermoelectric thermometer used for measuring air temperature. The name is derived from the fact that the reference thermocouple is placed in an insulated bottle.

Federal Aviation Administration.

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 balloon having a detachable tail which is released when the balloon has undergone a predetermined expansion. It thus serves to measure approximately the density of the atmosphere at the point of release.

The center of an area of high pressure, usually accompanied by anticyclonic and outward wind flow. Also known as an anticyclone.

Same as ombrometer.

Situated on the side from which the wind blows.

A form of data transmission in which the bits of each character are sent one at a time along a single communication path. Compare to parallel data transmission.

A hypothetical body which absorbs some constant fraction, between zero and one, of all electromagnetic radiation incident upon it, which fraction is the absorptivity and is independent of wavelength. Compare to black body, white body.

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 ...