An instrument used for measuring the specific gravity of a liquid.

Old snow that has become granular and compacted as a result of melting and refreezing.

See instrument error, observational error. random error, standard error, systematic error.

The amount of precipitation captured by a rain gauge.

Pertaining to the action or effect of the wind. Derived from the name of the Greek god of the winds, Aeolus.

A general term for atmospheric water in any of its forms, i.e. clouds, fog, hail, ice crystals, rain.

A unit of signaling speed representing the number of code elements sent per second; often, bits per second.

Anemometer which generates an electrical contact output with a frequency proportional to wind speed.

A graphical aid used in the reduction of data from a winds aloft observation.

A plastic molding component formed by the reaction of phenol and formaldehyde. It can be heavily reinforced or "filled" with glass fibers or other materials. Phenolics are known for their high impact strength, excellent wear characteristics, and dimension ...

The effect upon the measurement of rainfall caused by the presence of the rain gauge.

A halo phenomenon consisting of a horizontal circle passing through the moon, corresponding to the parhelic circle through the sun. Produced by reflection of moonlight from ice crystals.

A systematic summary of the terms (inflow, outflow, and storage) of the storage equation as applied to the computation of soil-moisture changes, ground-water changes, etc. An evaluation of the hydrologic balance of an area. Also called basin accounting, w ...

An instrument which measures the transmissivity of the atmosphere between two points for the determination of visual range.

The record obtained from a bolometer.

In general, solar radiation received at the earth's surface. Contracted from incoming solar radiation.

See approximate absolute temperature scale, Celsius temperature scale, centigrade temperature scale, Fahrenheit temperature scale, Kelvin temperature scale, Rankine temperature scale, Reaumur temperature scale,

That portion of the record of a microbarograph between any two (or a specified small number) of successive crossings of the average pressure level (in the same direction). Analogous to microseism.

The change in the measured transducer output caused by changes in ambient temperature. Usually expressed a percentage of full scale.

The total infrared radiation emitted from the earth's surface. To be carefully distinguished from atmospheric radiation, effective terrestrial radiation, and insolation.