Julius Bartels

Julius Bartels (August 17, 1899, Magdeburg – March 6, 1964) was a German geophysicist and statistician who made notable contributions to the physics of the Sun and Moon; to geomagnetism and meteorology; and to the physics of the ionosphere. He also made fundamental contributions to statistical methods for geophysics. Bartels was the first President of the International Association of Geomagnetism and Aeronomy. With Sydney Chapman, he wrote the influential book Geomagnetism.

Life and career

Bartels was awarded his Ph.D. from Göttingen in 1923, then worked at the Potsdam magnetic observatory as a post-doctorate. In 1928 he was named professor at Eberswalde, teaching meteorology. He became full professor at Berlin University in 1936, and director of the Potsdam Geophysical Institute. From 1931 until the second year of World War II he was also a research associate at the Carnegie Institution of Washington. He collaborated with Sydney Chapman to publish the two-volume work Geomagnetism, a definitive reference on geophysics.^[1]

In 1933 Bartels signed the Loyalty Oath of German Professors to Adolf Hitler and the National Socialist State.

Following the war in 1946 he became professor in Göttingen. He was also a director at the Max Planck Institute for Physics of the Stratosphere (today Max Planck Institute for Solar System Research) between 1955 and 1964. When 1958 ICSU created the Committee on Space Research (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 IUGG.^[2]

Research

Among his contributions was the development of the Kp-index, and he suggested the existence of "M-regions" on the Sun that resulted in geomagnetic activity. These coronal holes were later confirmed by the Skylab mission. Finally he also helped initiate the International Geophysical Year, which took place in 1957/8.

The Bartels' Rotation Number of the Sun based on a regular 27-day cycle is named after him.^[3] It is similar to the Carrington rotation which is based on 27.2753 days.

Awards and honors

• Posthumously awarded the William Bowie Medal of the American Geophysical Union.
• The Julius Bartels Medal, of the European Geosciences Union Division on Solar-Terrestrial Sciences, was named in his honor.^[4]
• The crater Bartels on the Moon is named after him.
• The Chree Medal and Prize in 1953

See also

• List of geophysicists

References

1. European Geosciences Union. "Awards & Medals: Julius Bartels". Retrieved September 2011. Check date values in: |access-date= (help)
2. A memorial note was published in Meteorlogische Rundschau 1964 by Wilfried Schröder.
3. Bartels, J. (1934). "Twenty-Seven Day Recurrences in Terrestrial-Magnetic and Solar Activity, 1923 1933". Terrestrial Magnetism and Atmospheric Electricity. 39 (3): 201–202a. Bibcode:1934TeMAE..39..201B. doi:10.1029/TE039i003p00201.
4. European Geosciences Union. "Awards & Honors: Julius Bartels Medal". Retrieved September 2011. Check date values in: |access-date= (help)

• Schröder, Wilfried (2010). "Sydney Chapman and his connections with some German geophysicists". Acta Geodaetica et Geophysica Hungarica. 44 (2): 245–254. doi:10.1556/AGeod.44.2009.2.10.
• Chapman, Sydney; Bartels, Julius (1940). Geomagnetism Volume 1: Geomagnetic and Related Phenomena. The International Series of Monographs on Physics. 6. ASIN B002K07MAO. OCLC 499431969.
• Chapman, Sydney; Bartels, Julius (1940). Geomagnetism Volume 2: Analysis of the Data and Physical Theories. The International Series of Monographs on Physics. 6. ASIN B0020TCMR8. OCLC 458641769.