IUGG: from different spheres to a common globe Hist. Geo Space Sci., 10, 163–172, 2019 https://doi.org/10.5194/hgss-10-163-2019 © Author(s) 2019. This work is distributed under the Creative Commons Attribution 4.0 License. IAGA: a major role in understanding our magnetic planet Mioara Mandea1 and Eduard Petrovský2 1Centre National d’Etudes Spatiales, 2 Place Maurice Quentin, 75001 Paris, France 2Institute of Geophysics, The Czech Academy of Sciences, Bocníˇ II/1401, 14131 Prague 4, Czech Republic Correspondence: Mioara Mandea ([email protected]) Received: 17 October 2018 – Revised: 15 December 2018 – Accepted: 4 January 2019 – Published: 16 April 2019 Abstract. Throughout the International Union of Geodesy and Geophysics’s (IUGG’s) centennial anniversary, the International Association of Geomagnetism and Aeronomy is holding a series of activities to underline the ground-breaking facts in the area of geomagnetism and aeronomy. Over 100 years, the history of these research fields is rich, and here we present a short tour through some of the International Association of Geomagnetism and Aeronomy’s (IAGA’s) major achievements. Starting with the scientific landscape before IAGA, through its foundation until the present, we review the research and achievements considering its complexity and variability, from geodynamo up to the Sun and outer space. While a number of the achievements were accomplished with direct IAGA involvement, the others represent the most important benchmarks of geomagnetism and aeronomy studies. In summary, IAGA is an important and active association with a long and rich history and prospective future. 1 Introduction IUGG General Assembly (Stockholm in 1930), the sections became associations, one of them being the International As- The International Association of Geomagnetism and Aeron- sociation of Terrestrial Magnetism and Electricity (IATME). omy (IAGA, Association Internationale de Géomagnétisme In 1951, the upper atmosphere scientists expressed their in- et d’Aéronomie – AIGA) is one of the eight associations of terest in being recognized in IATME. It was Sydney Chap- the International Union of Geodesy and Geophysics (IUGG). man who suggested using “geomagnetism” instead of “ter- It is a non-governmental body funded through the subscrip- restrial magnetism” and who created the term “aeronomy”, tions paid to IUGG by its Member Countries. IAGA is con- explained as “the science of the upper atmospheric regions cerned with the understanding and knowledge that result where dissociation and ionization are important”. In 1954, from studies of the magnetic and electrical properties of the again in Rome, during the 20th IUGG General Assembly, Earth’s core, mantle and crust, the middle and upper atmo- the newly created association adopted its present name, the sphere, the ionosphere and the magnetosphere, the Sun, the International Association of Geomagnetism and Aeronomy. solar wind, the planets and interplanetary bodies. IAGA has For more details on the history of IAGA, the reader is re- a long history and can trace its origin to the Commission for ferred to a comprehensive review by Fukushima (1995). Terrestrial Magnetism and Atmospheric Electricity, part of Since 2015, IAGA has been organized into six divisions the International Meteorological Organisation (IMO), which and four inter-divisional commissions, each led by a chair was established in 1873. Following World War I, the In- and a co-chair. Each division may form working groups in ternational Research Council was established, and at meet- given specialized topics, and elects officers to run the busi- ings in London and Paris in 1918, the IUGG (Union Geode- ness of the working groups. The working groups are the ele- sique et Geophysique Internationale in French) was formed, mentary cells of the association and at that level the main sci- with “Terrestrial Magnetism and Electricity (Magnétisme et entific activities of IAGA are designed. Division I deals with Electricité Terrestres)” as section D, with leadership given to the theory of planetary magnetic fields, paleomagnetism, and IMO. At the First IUGG General Assembly (Rome in 1922), rock and environmental magnetism. Division II aims at im- the Section of Terrestrial Magnetism and Electricity became proving the understanding of the dynamics, chemistry, en- one of the constituent sections of the union. During the IVth Published by Copernicus Publications. 164 M. Mandea and E. Petrovský: Major role of IAGA in understanding our magnetic planet ergetics and electrodynamics of the atmosphere–ionosphere system as well as the coupling processes. Division III is fo- cused on understanding how energy input from the Sun and solar wind influence and drive Earth’s magnetosphere and upper atmosphere. Division IV represents research fields re- lated to solar wind, the heliosphere, and solar magnetism. Division V deals with quality standards in geomagnetic data acquisition, observatory and survey procedures, geomagnetic indices, data dissemination, and analyses of magnetic data for the purpose of understanding the various sources of the magnetic field. Finally, activities of Division VI involve the investigation of all theoretical and practical aspects of the spatial distribution of electrical properties within the Earth’s and planetary interiors. Four inter-division commissions (on developing countries, history, education and outreach, and Figure 1. Participants of the first IAGA School, held in Merida, space weather) complete the internal IAGA structure. More- Mexico, in 2013, during the trip to inland Yucatan cenotas. over, IAGA is involved in several union and inter-association activities. The current activities of IAGA are due to efforts made during decades and even centuries by researchers in- volved in the Earth’s magnetism, aeronomy and solar mag- of the International Association of Meteorology and Atmo- netic field. The breadth and complexity of research carried spheric Sciences (IAMAS) from 1936 to 1948, President of out within IAGA was reflected in five volumes of the IAGA IAGA from 1948 to 1951, President of IUGG from 1951 to Special Sopron Book Series published by Springer. 1954, and President of the Special Committee for the Interna- Besides the scientific activities, IAGA also plays a major tional Geophysical Year, and Valery Troitskaya from the So- role in the exchange and dissemination of scientific infor- viet Union, who was the first woman president of any IUGG mation between the various scientific communities in devel- association (IAGA President between 1971 and 1975). oping countries. The Interdivisional Commission on Devel- In order to acknowledge significant scientific achieve- oping Countries aims to increase the participation of devel- ments as well as service to the community, IAGA presents oping countries in IAGA activities. Notable are the IAGA several medals and awards. The most prestigious is the Shen efforts for early career scientists. Since 2013, IAGA has or- Kuo Award, introduced in 2006 (IAGA News 43). Outstand- ganized the “IAGA School” (Fig. 1) during the week before ing long-term service to the IAGA community in technical the IAGA Scientific Assemblies and the IUGG General As- or managerial positions is acknowledged by the Long Ser- semblies with the aim of providing excellent early career sci- vice Award (introduced in 1988, IAGA News 27). The Young entists with a good basic understanding of a wide range of Scientist Award (introduced in 2005, IAGA News 43) is ad- the scientific topics covered by IAGA. The IAGA-sponsored dressed to young scientists for outstanding contributions at participants include the recipients of the IAGA Young Sci- meetings and workshops for which IAGA is a major spon- entist Awards, and a number of PhD students or young post- sor. Finally, since 1980 (IAGA News 19), a person who has docs, who are nominated by the IAGA Divisions and Work- given outstanding service to IAGA may be elected an Hon- ing Groups. The Interdivisional Commission on Education orary Member of IAGA. and Outreach is deeply involved in these activities. Information on the IAGA activities has been published The current structure of IAGA is presented at http://www. regularly since 1966 through the annual IAGA News (Fig. 3; iaga-aiga.org/ (last access: 18 January 2019). On the same all issues of the IAGA News are available on the IAGA web- website, information on how IAGA is administered by an Ex- site). The following statement can be found in the first issue ecutive Committee on behalf of IUGG Member Countries, in of the IAGA News: “One should express a wish that all the accordance with the Association’s Statutes and By-Laws, can investigators carrying on this work publish the information be found. The website provides a wide range of information quickly. This would give an opportunity to coordinate the about the association’s activities, from the meetings, prod- work, made by different investigators in different countries ucts and services to awards and honors. The full list of IAGA in a better way.” The role of IAGA is clearly noted. resolutions is also available, as well as all IAGA Newsletters. During the last century IAGA provided official (via resolu- The IAGA Presidents and Secretaries General have been tions) and organizational support to several high-profile sci- pioneers and well-known scientists in the modern world entific programmes, including the Second International Polar of geomagnetism and aeronomy, e.g. Aikitsu Tanakadate Year (IPY) in 1932–1933, the International Geophysical Year (Fig. 2). The full list of those who served IAGA can be found (IGY) in 1957–1958, the International Years of the Quiet Sun on the IAGA website. However, we have to mention here two (IQSY) in 1964–1965, and more recently, two international other great names: Sydney Chapman, who acted as President efforts in 2007–2008 to commemorate the 50th anniversary Hist. Geo Space Sci., 10, 163–172, 2019 www.hist-geo-space-sci.net/10/163/2019/ M. Mandea and E. Petrovský: Major role of IAGA in understanding our magnetic planet 165 The magnetic compass was used already in the 4th cen- tury BC in China.