Thermometer used for measuring the highest temperature attained during a given interval of time, for example, a day.

See ceilometer.

Readily taking up and retaining moisture.

Water vapor content of the air. See absolute humidity, dew point, mixing ratio, relative humidity, specific humidity.

An increase or amplification. There are two general usages of the term in radar meteorology: (a) antenna gain (or gain factor) is the ratio of the power transmitted along the beam axis to that of an isotropic radiator transmitting the same total power; an ...

Pyrheliometer based on the comparison of the heating of two identical metal strips, one exposed to radiation, the other to a joule effect.

See hydrologic accounting.

See feed.

Same as atmometer.

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,

Companion to the wet-bulb thermometer in a psychrometer. Used to measure ambient air temperature.

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

Precipitation caused by the ascent of moist air over an orographic barrier such as a Mountain range.

A large body of air having similar horizontal temperature and moisture characteristics.

Same as instrument shelter.

A small anemometer with flat vanes which indicates the number of linear feet or meters of air which have passed the instrument during its exposure.

An anemometer which measures wind speed by means of the properties of wind-borne sound waves. It operates on the principle that the propagation velocity of a sound wave in a moving medium is equal to the velocity of sound with respect to the medium plus t ...

A wave resulting from the action of wind on a water surface.

A wooden enclosure about sixteen feet square and eight feet high with a precipitation gauge at its center. The function of the fence is to minimize eddies around the gauge and thus insure a catch that is representative of the actual rainfall or snowfall.

A number of quantity defining a limit that errors will not exceed when a device is used under specified operating conditions. Accuracy rating can be expressed in a number of forms, i.e. in terms of the measured variable (+/- 1 C), percent of span (+/-0.5% ...