Julius Bartels (17 August 1899,

Magdeburg Magdeburg (; nds, label=Low Saxon, Meideborg ) is the capital and second-largest city of the German state Saxony-Anhalt. The city is situated at the Elbe river. Otto I, the first Holy Roman Emperor and founder of the Archdiocese of Magdebur ...

– 6 March 1964) was a German

geophysicist Geophysics () is a subject of natural science concerned with the physical processes and physical properties of the Earth and its surrounding space environment, and the use of quantitative methods for their analysis. The term ''geophysics'' som ...

and

statistician A statistician is a person who works with theoretical or applied statistics. The profession exists in both the private and public sectors. It is common to combine statistical knowledge with expertise in other subjects, and statisticians may wor ...

who made notable contributions to the physics of the

Sun The Sun is the star at the center of the Solar System. It is a nearly perfect ball of hot plasma, heated to incandescence by nuclear fusion reactions in its core. The Sun radiates this energy mainly as light, ultraviolet, and infrared radi ...

and

Moon The Moon is Earth's only natural satellite. It is the fifth largest satellite in the Solar System and the largest and most massive relative to its parent planet, with a diameter about one-quarter that of Earth (comparable to the width of ...

; to geomagnetism and

meteorology Meteorology is a branch of the atmospheric sciences (which include atmospheric chemistry and physics) with a major focus on weather forecasting. The study of meteorology dates back millennia, though significant progress in meteorology did not ...

; and to the physics of the

ionosphere The ionosphere () is the ionized part of the upper atmosphere of Earth, from about to above sea level, a region that includes the thermosphere and parts of the mesosphere and exosphere. The ionosphere is ionized by solar radiation. It plays an ...

. He also made fundamental contributions to statistical methods for geophysics. Bartels was the first President of the

International Association of Geomagnetism and Aeronomy The International Association of Geomagnetism and Aeronomy (IAGA) is an international scientific association that focuses on the study of terrestrial and planetary magnetism and space physics. IAGA is one of the eight associations of the Interna ...

(IAGA). With Sydney Chapman, he wrote the influential book '' Geomagnetism''.

Life and career

Bartels was awarded his

Ph.D. A Doctor of Philosophy (PhD, Ph.D., or DPhil; Latin: or ') is the most common degree at the highest academic level awarded following a course of study. PhDs are awarded for programs across the whole breadth of academic fields. Because it is ...

from

Göttingen Göttingen (, , ; nds, Chöttingen) is a college town, university city in Lower Saxony, central Germany, the Capital (political), capital of Göttingen (district), the eponymous district. The River Leine runs through it. At the end of 2019, t ...

in 1923, then worked at the

Potsdam Potsdam () is the capital and, with around 183,000 inhabitants, largest city of the German state of Brandenburg. It is part of the Berlin/Brandenburg Metropolitan Region. Potsdam sits on the River Havel, a tributary of the Elbe, downstream of B ...

magnetic observatory as a post-doctorate. In 1928, he was named

professor Professor (commonly abbreviated as Prof.) is an Academy, academic rank at university, universities and other post-secondary education and research institutions in most countries. Literally, ''professor'' derives from Latin as a "person who pr ...

Eberswalde Eberswalde () is a major town and the administrative seat of the district Barnim in the German State ( Bundesland / ''federated state'') of Brandenburg, about 50 km northeast of Berlin. Population 42,144 (census in June 2005), geographic ...

, teaching

. He became full professor at

Berlin University Humboldt-Universität zu Berlin (german: Humboldt-Universität zu Berlin, abbreviated HU Berlin) is a German public research university in the central borough of Mitte in Berlin. It was established by Frederick William III on the initiative o ...

in 1936, and director of the Potsdam Geophysical Institute. From 1931 until the second year of

World War II World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the vast majority of the world's countries—including all of the great powers—forming two opposin ...

, he was also a research associate at the

Carnegie Institution of Washington The Carnegie Institution of Washington (the organization's legal name), known also for public purposes as the Carnegie Institution for Science (CIS), is an organization in the United States established to fund and perform scientific research. Th ...

. He collaborated with Sydney Chapman to publish the two-volume work ''Geomagnetism'', a definitive reference on geophysics. In 1933, Bartels signed the ''

Vow of allegiance of the Professors of the German Universities and High-Schools to Adolf Hitler and the National Socialistic State Bekenntnis der Professoren an den Universitäten und Hochschulen zu Adolf Hitler und dem nationalsozialistischen Staat officially translated into English as the Vow of allegiance of the Professors of the German Universities and High-Schools to Ad ...

''. Following the war in 1946, he became professor in Göttingen. He was also a director at the

Max Planck Institute Max or MAX may refer to: Animals * Max (dog) (1983–2013), at one time purported to be the world's oldest living dog * Max (English Springer Spaniel), the first pet dog to win the PDSA Order of Merit (animal equivalent of OBE) * Max (gorilla) (1 ...

for Physics of the

Stratosphere The stratosphere () is the second layer of the atmosphere of the Earth, located above the troposphere and below the mesosphere. The stratosphere is an atmospheric layer composed of stratified temperature layers, with the warm layers of air ...

(today

Max Planck Institute for Solar System Research The Max Planck Institute for Solar System Research (abbreviation: MPS; german: Max-Planck-Institut für Sonnensystemforschung) is a research institute in astronomy and astrophysics located in Göttingen, Germany, where it relocated in February 201 ...

) between 1955 and 1964. When, in 1958

International Council for Science The International Council for Science (ICSU, after its former name, International Council of Scientific Unions) was an international non-governmental organization devoted to international cooperation in the advancement of science. Its members ...

, created the

Committee on Space Research The Committee on Space Research (COSPAR) was established on October 3, 1958 by the International Council for Scientific Unions (ICSU). Among COSPAR's objectives are the promotion of scientific research in space on an international level, wi ...

(''COSPAR''), Bartels became chairman of the West-German branch. From 1954 until 1957, he served as first President of the IAGA. Between 1960 and 1963, he was vice-president of the

International Union of Geodesy and Geophysics The International Union of Geodesy and Geophysics (IUGG; french: Union géodésique et géophysique internationale, UGGI) is an international non-governmental organization dedicated to the scientific study of Earth and its space environment us ...

Research

Among his contributions was the development of the Kp-index, and he suggested the existence of "M-regions" on the

that resulted in geomagnetic activity. These

coronal holes A coronal hole is a temporary region of relatively cool, less dense plasma (physics), plasma in the solar corona where the Sun's magnetic field extends into interplanetary space as an open field.Freedman, Roger A., and William J. Kaufmann III. "Ou ...

were later confirmed by the

Skylab Skylab was the first United States space station, launched by NASA, occupied for about 24 weeks between May 1973 and February 1974. It was operated by three separate three-astronaut crews: Skylab 2, Skylab 3, and Skylab 4. Major operations in ...

mission. Finally he also helped initiate the

International Geophysical Year The International Geophysical Year (IGY; french: Année géophysique internationale) was an international scientific project that lasted from 1 July 1957 to 31 December 1958. It marked the end of a long period during the Cold War when scientific ...

, which took place in 1957/8. The Bartels' Rotation Number of the Sun based on a regular 27-day cycle is named after him. It is similar to the Carrington rotation which is based on 27.2753 days.

Awards and honors

* Posthumously awarded the

William Bowie Medal The William Bowie Medal is awarded annually by the American Geophysical Union for "outstanding contributions to fundamental geophysics and for unselfish cooperation in research". The award is the highest honor given by the AGU and is named in honor ...

of the

American Geophysical Union The American Geophysical Union (AGU) is a 501(c)(3) nonprofit organization of Earth, atmospheric, ocean, hydrologic, space, and planetary scientists and enthusiasts that according to their website includes 130,000 people (not members). AGU's act ...

. * The ''Julius Bartels Medal'', of the

European Geosciences Union The European Geosciences Union (EGU) is a non-profit international union in the fields of Earth, planetary, and space sciences whose vision is to "realise a sustainable and just future for humanity and for the planet." The organisation has headq ...

Division on Solar-Terrestrial Sciences, was named in his honor. * The crater Bartels on the

is named after him. * The Chree Medal and Prize in 1953

References

* * * {{DEFAULTSORT:Bartels, Julius 1899 births 1964 deaths Scientists from Magdeburg People from the Province of Saxony German geophysicists University of Göttingen alumni German statisticians Members of the German Academy of Sciences at Berlin Members of the Göttingen Academy of Sciences and Humanities Max Planck Institute directors

Life and career

Research

Awards and honors

See also

References