Thermometer for measuring the temperature in the soil at different depths.

A mercury barometer designed for use aboard ship. The instrument is of the fixed-cistern type (see Kew barometer). The mercury tube is constructed with a wide bore for its upper portion and with a capillary bore for its lower portion. This is done to incr ...

Interational thermometric scale on which the freezing point of water equals 0

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 ...

General term for any device that measures precipitation: principally a rain gauge or snow gauge.

Moisture contained in the soil above the water table, including water vapor which is present in the soil pores. In some cases this term refers strictly to the humidity contained in the root zone of plants.

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

Wind with a speed between 4 and 6 knots (4 and 7 mph), Beaufort scale number 2.

Nested Grid Model generated every 12 hours by NCEP.

A device used by oceanographers to obtain subsurface samples of sea water. The "bottle" is lowered by wire, its valves open at both ends. It is then closed in situ by allowing a weight (called a messenger) to slide down the wire and strike the reversing m ...

A semiconductor which exhibits rapid and extremely large changes in resistance for relatively small changes in temperature.

The upward force produced by the gas in a balloon. It is equal to the free lift plus the weight of the balloon and the attached equipment.

Same as water year.

A balloon designed to float at a constant pressure level. This may be accomplished by a pressure valve which controls the release of ballast so as to maintain flight above a selected pressure level until the supply of ballast is exhausted. See Moby Dick b ...

Downward scattered and reflected solar radiation, coming from the whole hemisphere with the exception of the solid angle of the sun's disc on a surface perpendicular to the axis of this cone.

The indicating part of an instrument. For example, the hand of a watch or the meniscus of a mercury column.

A wave disturbance in airflow due to some barrier in the flow. i.e. a hill or mountain.

A generic term for any machine that enables a human being to communicate with a computer.

A protective coating applied to circuits.

Turbulence encountered by aircraft when flying through air space devoid of clouds. Thermals and wind shear are the main causes.