A cylinder installed in a body of water or an evaporation pan to hold a sensor, such as a float to measure water level or a hook gage. The stillwell is constructed so that there is free movement of water in and out of it, and it therefore provides a repre ...

A hygrometer in which the sensitive element is a strand or strands of human hair, the length of which is a function of the relative humidity of the air.

A series of Nansen-bottle water samples and associated temperature observations resulting from one release of a messenger.

A local variation in the wind direction or speed. This condition can present danger to aircraft, especially at landing, when a sudden shift from headwind to tailwind can cause a rapid loss of airspeed and lift.

The mass density of a parcel of air expressed in units of mass per volume.

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

The decrease of an atmospheric variable with height, the variable being temperature, unless otherwise specified.

Cathode Ray Tube. A display element, consisting of a vacuum tube and screen, used with computers.

The temperature at which an object gives out as much radiation as it receives from its surroundings.

To free something from the binding action of ice by warming it to a temperature above the melting point of ice. Also, a warm spell when ice and snow melt.

Abbreviation for binary digit. The smallest unit of information, equal to one binary decision, i.e. 1/0, on/off, yes/no.

An instrument for measuring the frost point of the atmosphere.

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

The sum of solar and terrestrial radiation.

Radiation with wavelengths greater than 4 microns. (In meteorology, same as infrared radiation.)

An instrument for determining the direction of cloud motion. There are two basic designs of nephoscope, the directvision nephoscope and the mirror nephoscope.

General name for an instrument which measures the evaporation rate of water into the atmosphere. See clay atmometer, evaporation pan, evapotranspirometer, Livingston sphere, Piche evaporimeter, radio atmometer.

A hygrometer using goldbeater's skin as the sensitive element. Variations of the physical dimensions of the skin caused by its hygroscopic character indicate relative humidity. (Note: Goldbeater's skin is the prepared outside membrane of the large intesti ...

A wind blowing in a direction opposite to the heading of a moving object, thus opposing the object's intended progress; the opposite of a tailwind.

The record made by a hygrograph.