Teisserenc de Bort , Léon Philippe

(1855–1913) French meteorologist

Teisserenc de Bort worked as chief meteorologist for the Central Meteorological Bureau in his native city of Paris from 1892 until 1896, when he opened his own meteorological observatory at Trappes, near Versailles.

In 1902 he put forward his conclusions on the atmosphere. Early balloonists had established that temperature decreased with height by about 6°C per 330 feet (100 m). Using unmanned instrumented balloons Teisserenc de Bort found that above an altitude of 7 miles (11 km) temperature ceased to fall and sometimes increased slightly. He named this upper part of the atmosphere the stratosphere, because he thought that the different gases would lie in distinct strata as, without temperature differentials, there would be no mechanism to disturb them. The lower part of the atmosphere he named the troposphere (Greek: ‘sphere of change’) as here, with abundant temperature differentials, constant change and mingling of atmospheric gases occurred.

The phenomenon was explained by E. Gold in 1909 by reference to cooling of rising air in the troposphere and the absence of convection currents in the stratosphere.