Solar radiation scattered by particles in the atmosphere.

The probability distribution of random errors, typically a normal distribution with a zero mean.

An instrument, located at the surface observing station, which is used to record the data presented by a radiosonde aloft.

That part of an audio-modulated radiosonde consisting of the baroswitch, the sensing elements, the reference elements, and the relay.

A captive balloon used to maintain meteorological equipment aloft at approximately a constant height. The kytoon is streamlined and combines the aerodynamic properties of a balloon and a kite.

Thermometer for measuring the temperature in the soil at different depths.

The flux of visible radiation, so weighted as to account for the manner in which the response of the human eye varies with the Wavelength of radiation. The basic unit for luminous flux is the lumen,

A small, limited-capacity central processing unit contained entirely on one semiconductor chip.

In meteorology, an area of low pressure; a low or trough.

Overflowing by water of the normal confines of a stream or other body of water, or accumulation of water by drainage over areas which are not normally submerged.

The record obtained from a bolometer.

The upward force produced by the gas in a balloon. It is equal to the free lift plus the weight of the balloon and the attached equipment.

See calorie.

The array of indicating marks and figure in relation to which the position of an index is observed, i.e. a scale plate on a recorder.

The rising of cold water from the deeper areas of the ocean to the surface. This phenomena often occurs along the California coast during the spring and summer.

The ratio of the actual amount of water evaporated into the atmosphere to the evaporative power. Also called relative evaporation.

A sudden brief increase in the speed of the wind, followed by a lull or slackening. Compare to peak gust.

The stage on a fixed river gauge at which it is necessary to begin issuing warnings or river forecasts if adequate precautionary measures are to be taken before flood stage is reached.

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

A unit of energy defined as the heat required to raise the temperature of one pound of water one degree Fahrenheit. It is equal to 252.1 calories or to 1055 joules.