A high-altitude sounding system consisting of a small solid- propellant research rocket carried aloft by a large plastic balloon. The rocket is fired near the maximum altitude of the balloon flight.

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 photoelectric spectrophotometer which is used in the determination of the ozone content of the atmosphere.

An anemometer in which the sensor rotation is transmitted to a mechanical counter which directly integrates the air movement past the sensor. Used to determine total air passage (wind run). Average wind speed can be calculated from the difference between ...

Programmable Read-Only Memory. Read-only memory which can be programmed by the user using a special hardware programmer.

A liquid-in-glass thermometer which uses an organic substance such as alcohol as the thermometer liquid. This type of thermometer has a low freezing point and a high coefficient of expansion. It is less accurate, however, than a mercury thermometer.

A hygrometer which includes an arrangement for the time recording of atmospheric humidity.

The value of the quantity measured, as indicated or otherwise provided by a measuring instrument.

Technically, the temperature registered by the dry-bulb thermometer of a psychrometer. However, it is identical with the temperature of the air and may also be used in that sense.

An air-launched balloon designed to be released in the eye of a tropical cyclone, float within the eye at predetermined levels, and transmit radio signals for RDF positioning.

A clay atmometer consisting of a hollow ceramic sphere through which evaporation occurs. Evaporation is measured by the loss of water from the reservoir which feeds the sphere.

The temperature to which a sample of air must be cooled, while the mixing ratio and barometric pressure remain constant, in order to attain saturation by water vapor. When this temperature is below O

A mercury-in-glass thermometer which records the temperature upon being inverted and retains its reading until being returned to the first position.

A class of rain gauge in which the level of the collected rain water is measured by the position of a float resting on the surface of the water.

The process by which water in plants is transferred as water vapor to the atmosphere. Also, the amount of water so transferred.

A measure, proposed by Angstrom, of the precipitation effectiveness of a region.

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.

Abbreviation for radio frequency.

A type of wind vane having a split or V-shaped tail. The apex orients itself to the direction of the wind.

A colorless and odorless gaseous element. The lightest and apparently the most abundant chemical element in the universe. However, it is found only in trace quantities in the observable portion of our atmosphere, only about 0.00005 percent by volume of dr ...