Thermometer in which the difference in the rates of expansion with temperature of a liquid and its receptacle is used as a measure of the temperature. The liquid used may be ethyl alcohol, toluene, petroleum, or mercury.

A flower-like diagram indicating the relative frequencies of different wind directions for a given station and period of time.

A protocol similar to RS232 which permits data interchange on multidrop networks of up to 32 nodes using a single twisted pair cable. In order for this protocol to be used, each device on a network must have some level of intelligence in order establish o ...

Wind with a speed between 34 and 40 knots (39 and 46 mph); Beaufort scale number 8.

Electromagnetic radiation of very short wavelength. lying within the wavelength interval of 0.1 to 1.5 angstroms (between gamma rays and ultraviolet radiation). X-rays penetrate various thicknesses of all solids, and they act on photographic plates in the ...

That part of snow melt that reaches stream channels as runoff.

Amount of water, expressed as a depth or as a mass, which would be obtained if all the water vapor in a specified column of the atmosphere were condensed and precipitated.

The water portion of the earth as distinguished from the solid part, called the lithosphere, and from the gaseous outer envelope, called the atmosphere.

A small balloon used to determine the height of the cloud base. The height can be computed from the ascent velocity of the balloon and the time required for its disappearance into the cloud.

A liquid-in-metal thermometer in which mercury is enclosed in a steel envelope. The change in internal pressure caused by the temperature variation is measured by a Bourdon tube which is connected to the mercury by a capillary tube. This instrument is hig ...

The time required for an instrument to register a designated percentage (frequently 90%) of a step change in the variable being measured.

Same as parhelion.

One of the radiation laws which states that the wavelength of maximum radiation intensity for a black body is inversely proportional to the absolute temperature of the radiating black body.

Upwarddirected solar radiation, reflected by the earth's surface and the atmosphere.

Lowest altitude in the atmosphere over a given location at which the air temperature is 0

A graphical representation of a frequency distribution. The range of the variable is divided into class intervals for which the frequency of occurrence is represented by a rectangular column. The height of the column is proportional to the frequency of ob ...

The record of an aneroid barograph.

An instrument which measures the intensity of radiation by determining the amount of chemical change( or fluorescence produced by that radiation.

A curve showing the variation of temperature with height in the free air. See lapse rate.

An instrument for measuring angles of inclination. Used in conjunction with a ceiling light to measure cloud height at night.