A radiosonde which is dropped by parachute from an aircraft for the purpose of obtaining soundings of the atmosphere below.

The boundary between the troposphere and stratosphere, usually characterized by an abrupt change in lapse rate. Its height varies from 10 to 20 km. Regions above the tropopause have greater atmospheric stability than regions below.

A device for computing certain psychrometric data, usually the dew point and the relative humidity, from known values of the dry-bulb and wet-bulb temperatures and the atmospheric pressure. One type is the circular slide-rule form and, like the psychromet ...

Same as parhelion.

A line drawn through all points on a map having the same amount of cloudiness.

A type of cistern barometer in which the level of mercury in the cistern is adjusted to the zero point of the scale before each reading.

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.

A mercury barometer in which the tube is U-shaped and the upper and lower mercury surfaces have the same diameter.

In general. the severe wind of an intense tropical cyclone (hurricane or typhoon). The term has no further technical connotation, but, unfortunately, is easily conftlsed with the strictly defined hurricane-force wind,

The study of waters (including oceans, lakes, and rivers) embracing either: (a) their physical characteristics, from the standpoint of the oceanographer or limnologist; or (b) the elements affecting safe navigation, from the point of view of the mariner. ...

Same as precipitation- effectiveness index.

The total electromagnetic radiation emitted by the sun. About 99.9 percent of its energy output falls within the wavelength interval from 0. 15 microns to 4.0 microns, with peak intensity near 0.47 microns. About one-half of the total energy in the solar ...

Of equal or constant pressure, with respect to either space or time.

Wind with a speed between 28 and 33 knots (32 and 38 mph); Beaufort scale number 7.

Any conventional barometer fitted with an extended scale so that atmospheric pressure measurements may be made at both high and low altitudes.

The physical exposure of an instrument. The effect of immediate environment upon the representativeness of the measurements obtained by meteorological instruments is considerable and not always correctable. The purpose of the instrument shelter is to prov ...

The humidity transducinu element in a Diamond-Hinman radiosonde. Also called electrolytic strip.

The point (physical and/or electrical) where two distinct data processing elements meet.

See stage.

An instrument for measuring the intensity of light or the relative intensity of a pair of lights. Also called an illuminometer. If the instrument is designed to measure the intensity of light as a function of wavelength, it is called a spectrophotometer. ...