Léon Philippe Teisserenc de Bort (November 5, 1855 in
ParisParis is the capital and largest city in France, situated on the river Seine, in northern France, at the heart of the Île-de-France region...
,
FranceThe French Republic , The French Republic , The French Republic , (commonly known as France , is a unitary semi-presidential republic in Western Europe with several overseas territories and islands located on other continents and in the Indian, Pacific, and Atlantic oceans. Metropolitan France...
– January 2, 1913 in
CannesCannes is one of the best-known cities of the French Riviera, a busy tourist destination and host of the annual Cannes Film Festival. It is a Commune of France in the Alpes-Maritimes department....
, France) was a
FrenchThe French Republic , The French Republic , The French Republic , (commonly known as France , is a unitary semi-presidential republic in Western Europe with several overseas territories and islands located on other continents and in the Indian, Pacific, and Atlantic oceans. Metropolitan France...
meteorologistMeteorology is the interdisciplinary scientific study of the atmosphere. Studies in the field stretch back millennia, though significant progress in meteorology did not occur until the 18th century. The 19th century saw breakthroughs occur after observing networks developed across several countries...
who became famous for his discovery of the
stratosphereThe stratosphere is the second major layer of Earth's atmosphere, just above the troposphere, and below the mesosphere. It is stratified in temperature, with warmer layers higher up and cooler layers farther down. This is in contrast to the troposphere near the Earth's surface, which is cooler...
. He pioneered the use of unmanned instrumented
balloonsA weather or sounding balloon is a balloon which carries instruments aloft to send back information on atmospheric pressure, temperature, humidity and wind speed by means of a small, expendable measuring device called a radiosonde...
and was the first to identify the region in the
atmosphereThe atmosphere of Earth is a layer of gases surrounding the planet Earth that is retained by Earth's gravity. The atmosphere protects life on Earth by absorbing ultraviolet solar radiation, warming the surface through heat retention , and reducing temperature extremes between day and night...
around 8-17 kilometers of height where the lapse rate reaches zero, known today as the
tropopauseThe tropopause is the atmospheric boundary between the troposphere and the stratosphere.-Definition:Going upward from the surface, it is the point where air ceases to cool with height, and becomes almost completely dry...
.
Early life and career
He was the son of an engineer. He began his scientific career in 1880, when he entered the meteorological department of the Bureau Central Météorologique (Administrative Center of National Meteorology, a department of the French government) in
ParisParis is the capital and largest city in France, situated on the river Seine, in northern France, at the heart of the Île-de-France region...
under
E. E. N. MascartÉleuthère Élie Nicolas Mascart was a noted French physicist, a researcher in optics and electricity.Mascart was born in Quarouble, Nord. He attended the École normale supérieure...
. In 1883, 1885 and 1887 he made journeys to
North AfricaNorth Africa or Northern Africa is the northernmost region of the African continent, linked by the Sahara to Sub-Saharan Africa. Geopolitically, the United Nations definition of Northern Africa includes eight countries or territories; Algeria, Egypt, Libya, Morocco, South Sudan, Sudan, Tunisia, and...
to study geology and terrestrial magnetism, and during this, period published some important charts of the distribution of pressure at a height of 4,000 metres. Between 1892 and 1896, Teisserenc de Bort was chief meteorologist to the Bureau.
Instrumented balloons pioneer
After his resignation from the Bureau in 1896, he established a private meteorological observatory in
TrappesTrappes is a commune in the Yvelines department in the Île-de-France in north-central France. It is located in the western suburbs of Paris from the center in the new town of Saint-Quentin-en-Yvelines.-Transport:...
near
VersaillesVersailles , a city renowned for its château, the Palace of Versailles, was the de facto capital of the kingdom of France for over a century, from 1682 to 1789. It is now a wealthy suburb of Paris and remains an important administrative and judicial centre...
. There he carried out investigations on clouds and the problems of the upper air. He conducted experiments with high-flying instrumented
hydrogenHydrogen is the chemical element with atomic number 1. It is represented by the symbol H. With an average atomic weight of , hydrogen is the lightest and most abundant chemical element, constituting roughly 75% of the Universe's chemical elemental mass. Stars in the main sequence are mainly...
balloons and was one of the first people to use such devices.
In 1898, Teisserenc de Bort published an important paper in
Comptes Rendus detailing his researches by means of balloons into the constitution of the atmosphere. He noticed that while the air
temperatureTemperature is a physical property of matter that quantitatively expresses the common notions of hot and cold. Objects of low temperature are cold, while various degrees of higher temperatures are referred to as warm or hot...
decreased steadily up to approximately 11 kilometers of height, it remained constant above that
altitudeAltitude or height is defined based on the context in which it is used . As a general definition, altitude is a distance measurement, usually in the vertical or "up" direction, between a reference datum and a point or object. The reference datum also often varies according to the context...
(up to the highest points he could reach). In other words, he discovered an indication of a temperature inversion or at least of a zero lapse rate above this altitude. For many years he was uncertain whether he discovered a true physical phenomenon or whether his measurements suffered from a systematic
biasBias is an inclination to present or hold a partial perspective at the expense of alternatives. Bias can come in many forms.-In judgement and decision making:...
(indeed, the first measurements
did have a positive temperature bias as the instruments were liable to radiative heating by solar radiation). That is why Teisserenc de Bort carried out 200+ more balloon experiments (with a substantial part of them being held during the night to eliminate radiative heating) until 1902, when he suggested that the atmosphere was divided into two layers.
Troposphere and stratosphere
During the years that followed, he named the two
layers of the atmosphereThe atmosphere of Earth is a layer of gases surrounding the planet Earth that is retained by Earth's gravity. The atmosphere protects life on Earth by absorbing ultraviolet solar radiation, warming the surface through heat retention , and reducing temperature extremes between day and night...
known as the "
troposphereThe troposphere is the lowest portion of Earth's atmosphere. It contains approximately 80% of the atmosphere's mass and 99% of its water vapor and aerosols....
" and the "
stratosphereThe stratosphere is the second major layer of Earth's atmosphere, just above the troposphere, and below the mesosphere. It is stratified in temperature, with warmer layers higher up and cooler layers farther down. This is in contrast to the troposphere near the Earth's surface, which is cooler...
". This naming convention has since been maintained, with (higher-altitude) layers that were subsequently discovered being given names of this sort. After Teisserenc de Bort's death in 1913, the heirs donated the observatory to the state so that the research tasks could be continued.
Additional investigations
He also carried out investigations in
SwedenSweden , officially the Kingdom of Sweden , is a Nordic country on the Scandinavian Peninsula in Northern Europe. Sweden borders with Norway and Finland and is connected to Denmark by a bridge-tunnel across the Öresund....
and over the
Zuider ZeeThe Zuiderzee was a shallow bay of the North Sea in the northwest of the Netherlands, extending about 100 km inland and at most 50 km wide, with an overall depth of about 4 to 5 metres and a coastline of about 300 km . It covered...
, the Mediterranean and the tropical region of the Atlantic, and fitted out a special vessel in order to study the currents above the trade winds. He was elected a fellow of the
Royal Meteorological SocietyThe Royal Meteorological Society traces its origins back to 3 April 1850 when the British Meteorological Society was formed as a society the objects of which should be the advancement and extension of meteorological science by determining the laws of climate and of meteorological phenomena in general...
in 1903, honorary member in 1909, and was awarded the Symons gold medal of the Society in 1908. He collaborated with Hugo Hildebrandsson in
Les bases de la météorologie dynamique (1907).
Named after him
- The crater Teisserenc
Teisserenc is an eroded lunar impact crater on the Moon's far side. It lies just to the east of the crater Sanford, and southwest of Charlier. To the east of Charlier lies Kovalevskaya....
on the MoonThe Moon is Earth's only known natural satellite,There are a number of near-Earth asteroids including 3753 Cruithne that are co-orbital with Earth: their orbits bring them close to Earth for periods of time but then alter in the long term . These are quasi-satellites and not true moons. For more...
.
- The crater Teisserenc de Bort on Mars
Mars is the fourth planet from the Sun in the Solar System. The planet is named after the Roman god of war, Mars. It is often described as the "Red Planet", as the iron oxide prevalent on its surface gives it a reddish appearance...
.
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