A thermometer designed for use in measuring the temperature of sea water. One form consists of a mercury-in-glass thermometer protected by a perforated metal case. Another form consists of a mercury-in-glass thermometer surrounded by a metal case which fo ...

A device for measuring the river stage. Also called stream gauge.

A basic equation in daytime visual range theory, relating the apparent luminance of a distant black object, the apparent luminance of the background sky above the horizon, and the extinction coefficient of the atmosphere, or the air layer near the ground. ...

The rate of decrease of temperature with height when unsaturated air is lifted adiabatically (without exchange of heat with its surroundings). The decrease is due to expansion as the air is lifted to a lower pressure.

A measurement of atmospheric conditions aloft, above the effective range of a surface weather observation. Elements evaluated include temperature, humidity, pressure, wind speed, and wind direction.

The envelope of air surrounding the earth and bound to it more or less permanently by virtue of the earth's gravitational attraction. The system whose chemical Properties. dynamic motions, and physical processes constitute the subject matter of meteorolog ...

A component of a radiosonde consisting of a series of alternate electrically conducting and insulating strips. As these are scanned by a contact the radiosonde transmits temperature and humidity signals alternately. The contact may be a baroswitch as in t ...

The lowest value of a measured quality at which a sensor meets its accuracy specification.

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

A recording weight barometer.

A device used to switch electrical current at a selectable setpoint temperature.

An instrument designed to measure quantities of heat. Sometimes used in meteorology to measure solar radiation.

Pertaining to measurements or devices in which the output varies continuously, i.e. voltage or rotation signals. Compare to digital.

A relatively small-scale, downward moving current of air.

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. ...

A recording anemoclinometer.

A type of instrument shelter. It is a wooden box painted white with double louvered sides and mounted on a stand four feet above the ground.

Wind with a speed between 4 and 27 knots (4 and 31 mph); Beaufort scale numbers 2 through 6.

An instrument used for measuring geometric angles. See radio direction-finder.

Operation mode of a communication circuit in which each end can transmit and receive, but not simultaneously.