https://stm2.bookpi.org/DBCPGISC <p>The linkage between weather and climate on one hand and aurora, geomagnetism, and radio disturbances on the other is not obvious nowadays. However, for more than a century, the Danish Meteorological Institute has provided national weather services and has also been an internationally recognised Centre for research in auroras, geomagnetism and radio disturbances.</p> <p>The first regular Danish auroral observations were made by the astronomer, Tycho Brahe, from the small island, Hven, in the strait between Denmark and Sweden. His observations of weather and auroras (“chasmata”) were noted in the “Meteorologische Journalen” during the years 1582-92. His notes were later published by Poul la Cour (father of Dan B. la Cour) in 1876.</p> <p>The relations between auroras and geomagnetic variations were made realistic by H. C. Ørsted’s discovery of the magnetic effect on electric currents in 1820 and solidified in 1823 by the publication of his view on aurora theories. “The luminous arc in large auroras has precisely the same orientation as that of an electrical discharge with corresponding magnetic effects”. Ørsted was also the founder of a permanent Meteorological Committee in 1827, which developed into the foundation of the Danish Meteorological Institute (DMI) in 1872.</p> <p>In 1963, I was employed at the Ionosphere Laboratory headed by Professor J. Rybner at the Danish Technical University to be a lecturer in plasma physics and radio wave propagation, and also to work with geophysical observations from Greenland. The Ionosphere Laboratory (Ionlab) in 1968 was transferred to the Meteorological Institute.</p> <p>At the Institute’s 100 years anniversary in 1972, in addition to divisions for weather services, climatology, aerology, nautical services, and operation of weather equipment and observatories in Denmark, Faroe Island and Greenland, and in addition to Ionlab, there were already two geophysical division (GEI and GEII) dealing with auroras and geomagnetism and building precision magnetic instruments, and furthermore an international division comprising the Copenhagen World Data Centre (WDC) for Geomagnetism.</p> <p>Thus, beyond the meteorological services, the Danish Meteorological Institute had very diverse teams with profound knowledge and wide experiences in many aspects of geophysics, including auroras, geomagnetism, and radio wave propagation. This became the background for comprehensive geophysical activities, including numerous scientific publications and operation of geomagnetic observatories, one in Denmark, and 16 in Greenland, of which many were also equipped with instrumentation for auroral and radio wave observations. The skilled geophysical teams at DMI were also the basis for assuming a leading position in the development of the first Danish satellite, “Ørsted”, successfully launched in 1999.</p> en-US Dan Barfod la Cour: Pioneer of Geomagnetism and International Scientific Cooperation https://stm2.bookpi.org/DBCPGISC/article/view/620 <p>Dan Barfod la Cour (1876–1942) was a distinguished scientist, instrument constructor, and international coordinator in geomagnetism and meteorology. He was the son of Poul la Cour, a Danish physicist who served as deputy director of the Danish Meteorological Institute (MI, now DMI) and later as professor at Askov Folk University. Dan la Cour matriculated from Lyceum in 1895, completed his military service in 1896–97, and worked as a science assistant at the University of Copenhagen from 1897–99. He obtained his M.Sc. degree from Copenhagen University in 1902 and became assistant professor at the Technical University in 1908. Dan la Cour participated in DMI aurora expeditions to Iceland and Finland during 1899–1901 and was employed at DMI in 1900. He became head of the DMI weather department in 1903, head of the department of geomagnetism in 1920, and served as director of DMI from 1923 until his death in 1942.</p> <p>Dan la Cour was a brilliant instrument builder who constructed precision instruments for geomagnetic measurements, including the Copenhagen Variometer, the Godhavn Balance and BMZ vertical intensity variometers, and the QHM quartz horizontal magnetometer. These instruments were manufactured in Copenhagen and supplied to magnetic observatories worldwide during 1930–50. In 1925, he established a magnetic observatory in Godhavn, the first in Greenland, and initiated magnetic observations from Thule and Julianehaab, Greenland, during the Polar Year 1932–33.</p> <p>Dan la Cour served the international scientific community as President of the Polar Year Commission from 1929, as Secretary of the International Association of Terrestrial Magnetism and Electricity from 1933 to1936, and as President of the International Union of Geodesy and Geophysics from 1936 to 1942.</p> Peter Stauning Copyright (c) 2025 Author(s). The licensee is the publisher (BP International). 2025-11-17 2025-11-17 1 94 10.9734/bpi/mono/978-93-88417-19-8