HOPKINS GLOSSARY OF WEATHER TERMS T

target

telemetry

• The study of the remote sensing and measurement of quantities.

theodolite

• An optical or radio instrument used to make accurate measurements of vertical and horizontal angles; used in tracking instrument packages on weather balloons and rockets. Optical theodolites use a telescope to aid in tracking.

thermistor

• A type of electrical therometer whose electrical resistance decreases markedly and monotonically as the temperature increases. This instrument is often used on radiosondes or rocketsondes .

thermogram

• A continuous trace of temperature variation with time, typically produced by a thermograph.

thermograph

• A self-recording thermometer that produces a permanent thermogram.

thermometer

• Any instrument that measures temperature with a sensor element that utilizes the variation of the physical properties of a substances associated with their temperature. Examples include liquid-in-glass , deformation-type, electrical and radiation thermometers.

thermosphere

• The region of the earth's atmosphere above the mesopause , starting at 80 km (50 mi) altitude, where the air temperature increases with altitude. The thermosphere extends outward toward space and includes the exosphere and most or all of the ionosphere.

transponder

• A miniature receiver-transmitter that can be tracked by a radio-direction finder.

tropopause

• The cold region in the earth's atmosphere located about 10 km (8 mi) above the surface, at which the usual vertical temperature decrease in the troposphere ceases; by convention, the tropopause is defined as where the temperature lapse rate to less than 2 C per kilometer for an extended depth (usually 2 km). This boundary marks the top of the troposphere and the base of the stratosphere, and can vary with season and latitude, with a altitude ranging from 6 km (4 mi) in polar regions to 16 km (10 mi) in the tropics

troposphere

• The lowest region of the earth's atmosphere that extends from the surface to the tropopause, located at an altitude of 6 to 16 km (4 to 10 mi). Normally this region has a more or less regular decrease of air temperature with increasing altitude, considerable vertical wind motion, appreciable water vapor, and weather.