A thermometer consisting of a clock mechanism the speed of which is a function of temperature.

A line drawn through geographical points having the same pluvial index.

Instrument for measuring the mean intensity of glo global solar radiation (direct and diffuse) near the earth's surface in a specified time interval.

A temperature telemeter.

A medium-sized instrument shelter. It is a white louvered box with a flat double to of and is mounted four feet above the ground on a four-legged stand.

Not a linear function of the relevant variables.

Graduated fixed stake used in regions of abundant snowfall to facilitate the measurement of snow depth.

A standard unit of atmospheric pressure, defined as the pressure exerted by a 760 mm column of mercury at standard gravity (980.665 cm/sec2 ) at O

A measure of the intensity of gusts given by the ratio of the total range of wind speed between gusts and the intermediate periods of lighter wind to the mean wind speed, averaged over both gusts and lulls.

Same as aneroid barometer. Holostelic means wholly made of solids, while aneroid means devoid of liquid.

Radiation with wavelengths less than 4 microns.

An element that can control current without moving parts, heated filaments, or vacuum gaps.

See sea-water thermometer, reversing thermometer.

A general term to designate apparatus designed to observe the details of weather during thunderstorms.

Of equal or constant pressure, with respect to either space or time.

An air-launched balloon designed to be released in the eye of a tropical cyclone, float within the eye at predetermined levels, and transmit radio signals for RDF positioning.

Very small precipitation drops (diameters less than 0.5 mm) that appear to float with air currents while falling in an irregular path. Unlike fog droplets, drizzle falls to the ground.

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

A type of wind vane having a split or V-shaped tail. The apex orients itself to the direction of the wind.

The general term for anemometers operating on the principle that the heat transfer to air from an object at an elevated temperature is a function of the air speed. Examples are the hot-wire anemometer and the katathermometer.