Tor Bergeron (15 August 1891 – 13 June 1977) was a
Swedish
Swedish or ' may refer to:
Anything from or related to Sweden, a country in Northern Europe. Or, specifically:
* Swedish language, a North Germanic language spoken primarily in Sweden and Finland
** Swedish alphabet, the official alphabet used by ...
meteorologist
A meteorologist is a scientist who studies and works in the field of meteorology aiming to understand or predict Earth's atmospheric phenomena including the weather. Those who study meteorological phenomena are meteorologists in research, while t ...
who proposed a mechanism for the formation of
precipitation
In meteorology, precipitation is any product of the condensation of atmospheric water vapor that falls under gravitational pull from clouds. The main forms of precipitation include drizzle, rain, sleet, snow, ice pellets, graupel and hail. ...
in
cloud
In meteorology, a cloud is an aerosol consisting of a visible mass of miniature liquid droplets, frozen crystals, or other particles suspended in the atmosphere of a planetary body or similar space. Water or various other chemicals may ...
s. In the 1930s, Bergeron and W. Findeisen developed the concept that clouds contain both supercooled water and ice crystals. According to Bergeron, most precipitation is formed as a consequence of water evaporating from small supercooled droplets and accreting onto ice crystals, which then fall as
snow
Snow comprises individual ice crystals that grow while suspended in the atmosphere—usually within clouds—and then fall, accumulating on the ground where they undergo further changes.
It consists of frozen crystalline water throughout ...
, or melt and fall as cold
rain
Rain is water droplets that have condensed from atmospheric water vapor and then fall under gravity. Rain is a major component of the water cycle and is responsible for depositing most of the fresh water on the Earth. It provides water ...
depending on the ambient air temperature. This process is known as the
Bergeron Process
Bergeron is a surname of French origin.
The name Bergeron may be derived from the Old German word ''berg'', meaning hill or mountain. It may also be derived from the old French ''berger'', meaning shepherd.
Spelling variations include: Bergetr ...
, and is believed to be the primary process by which precipitation is formed.
Bergeron was one of the principal scientists in the
Bergen School of Meteorology __NOTOC__
The "Bergen School of Meteorology" is a school of thought which is the basis for much of modern weather forecasting.
Founded by the meteorologist Prof. Vilhelm Bjerknes and his younger colleagues in 1917, the Bergen School attempts to de ...
, which transformed this science by introducing a new conceptual foundation for understanding and predicting weather. While developing innovative methods of forecasting, the Bergen scientists established the notion of weather fronts and elaborated a new model of extratropical cyclones that accounted for their birth, growth, and decay. Bergeron is credited with discovering the
occlusion process, which marks the final stage in the life cycle of an
extratropical cyclone.
In 1949 he was awarded the
Symons Gold Medal of the
Royal Meteorological Society.
In 1966 he was awarded the prestigious
International Meteorological Organization Prize from the
World Meteorological Organization
The World Meteorological Organization (WMO) is a specialized agency of the United Nations responsible for promoting international cooperation on atmospheric science, climatology, hydrology and geophysics.
The WMO originated from the Intern ...
.
References
*A complete bibliography for Bergeron can be found in Liljequist (1981):
** Liljequist, Gösta H. “Tor Bergeron: A Biography.” Pure and Applied Geophysics 119 (1981): 409–442.
{{DEFAULTSORT:Bergeron, Tor
1891 births
1977 deaths
Swedish meteorologists
British emigrants to Sweden