108 Atmospheric Layers
Teisserenc de Bort found that tracking the basket and parachute were more difficult
than he first thought, even when he used a telescope. Each launch involved a mad scramble
across the countryside to keep the descending package in sight. Even so, a few were never
found, some sunk in rivers or lakes, and some were smashed when the parachutes failed.
Still, Teisserenc de Bort persisted—and was amazed at what he discovered. Atmospheric temperature decreased steadily at a constant rate of 6.5°C per kilometer of altitude
(19°F per mile). This decrease was expected.
However, at an altitude of around 11 km (7 miles, or about 37,000 feet) the temperature stopped decreasing at all. It remained level at around -53°C up to over 48,000 feet (as
high as Teisserenc de Bort’s balloons would fly).
At first Teisserenc de Bort didn’t believe that the temperature could possibly stop decreasing. He suspected that the instruments rose to a height where solar heating warmed the
thermometer and compensated for continued atmospheric temperature decrease.
He began to launch at night. It was harder to track the parachute’s descent, but it prevented any possibility of solar heating. Even at night, his results were the same. The temperature above 11 km remained constant.
After 234 tests, Teisserenc de Bort finally concluded that his measurements were accurate and that there were two, separate layers to the atmosphere. Near the surface lay an
11-km-thick lower layer where temperature changes created currents, winds, clouds, and
weather. Above that was a region where constant temperature allowed air to settle into
quiet, undisturbed layers
He named the lower layer the troposphere, from the Greek words meaning “sphere of
change,” and the upper layer the stratosphere, from the Greek words meaning “sphere of
layers.”
Teisserenc de Bort’s discovery is still the basis of our understanding of the atmosphere.
Fun Facts: Scientists now know that the atmosphere has many layers,
but the troposphere is the layer where all of Earth’s weather occurs.
More to Explore
Emanuel, Kerry. Atmospheric Convection. New York: Oxford University Press, 1997.
Hewitt, C. N., ed. Handbook of Atmospheric Science: Principles and Applications.
Boston: Blackwell Publishers, 2003.
Jones, Phil. History and Climate. London: Kluwer Academic Press, 2001.
Parker, Sybil, ed. McGraw-Hill Encyclopedia of Ocean and Atmospheric Sciences.
New York: McGraw-Hill, 1997.
Stull, Ronald. Introduction to Boundary Layer Meteorology. London: Kluwer Academic Press, 1998.
Wallace, John. Atmospheric Science, First Edition: An Introductory Survey. New
York: Academic Press, 1997.