The record made by a hygrograph.

The lowest level at which the wind becomes geostrophic in the theory of the Ekman spiral. Also called gradient wind level.

A sudden brief increase in the speed of the wind, followed by a lull or slackening. Compare to peak gust.

A captive balloon used to maintain meteorological equipment aloft at approximately a constant height. The kytoon is streamlined and combines the aerodynamic properties of a balloon and a kite.

A rainbow formed by light rays which have been reflected from an extended water surface. Not to be confused with a reflected rainbow whose image may be seen in a still body of water. The center of a reflection rainbow is at the same elevation as the sun b ...

A large plastic constant-level balloon for duration flying (in excess of 24 hours) at altitudes above 40,000 feet, used for the determination of wind fields and the measurement of upper atmospheric parameters.