Solar radiation of selected wavelengths.

The amount of precipitation captured by a rain gauge.

An instrument used to measure the amount of dew formed on a given surface.

The ratio of the output of an instrument to the input value, i.e. a rain gauge with a sensitivity of 1 tip per 0.01"

The cardinal points of the compass, i.e. north, south, east, west.

Of or pertaining to rain.

An instrument which records the duration of sunshine and gives a quantitative measure of the amount of sunshine by the action of the sun's rays upon blueprint paper. A type of sunshine recorder.

A transducer for converting thermal energy directly into electrical energy. It is composed of pairs of thermocouples which are connected either in series or in parallel. Thermopiles are used in thermoelectric radiation instruments when the output of a sin ...

Same as river gauge.

A photometer which measures the intensity of radiation as a function of the frequency (or wavelength) of the radiation.

The direction from which the wind is blowing, measured in points of the compass or in azimuth degrees.

The actual lifting force of an inflated balloon, usually expressed in grams.

check chamber-A chamber use to check the sensing elements of radiosonde equipment.

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 ...

For a given location, a measure of the long-range effectiveness of precipitation in promoting plant growth. Also called precipitation-evaporation index.

Meteorological information issued by a watch office concerning the occurrence or forecast of weather phenomena which may affect the safety of aircraft operations.

The group of bits which a computer processes as a unit; often, 8 bits.

A precipitation amount of less than 0.005 inches. Also, the record made by any self-registering instrument.

A type of photoelectric photometer used to measure high-altitude winds on the assumption that stellar scintillation is caused by atmospheric inhomogeneities being carried along by wind near the tropopause level.

Automated Surface Observing System. A network of instrumented weather stations deployed primarily by the National Weather Service to make weather observations without operator involvement.