The Magnetic Field of Planet Earth

The magnetic field of the Earth is by far the best documented magnetic field of all known planets. Considerable progress has been made in our understanding of its characteristics and properties, thanks to the convergence of many different approaches and to the remarkable fact that surface rocks have quietly recorded much of its history. The usefulness of magnetic field charts for navigation and the dedication of a few individuals have also led to the patient construction of some of the longest series of quantitative observations in the history of science. More recently even more systematic observations have been made possible from space, leading to the possibility of observing the Earth’s magnetic field in much more details than was previously possible. The progressive increase in computer power was also crucial, leading to advanced ways of handling and analyzing this considerable corpus G. Hulot ( ) Equipe de Géomagnétisme, Institut de Physique du Globe de Paris (Institut de recherche associé au CNRS et à l’Université Paris 7), 4, Place Jussieu, 75252, Paris, cedex 05, France e-mail: [email protected] C.C. Finlay ETH Zürich, Institut für Geophysik, Sonneggstrasse 5, 8092 Zürich, Switzerland C.G. Constable Cecil H. and Ida M. Green Institute of Geophysics and Planetary Physics, Scripps Institution of Oceanography, University of California at San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0225, USA N. Olsen DTU Space and Niels Bohr Institute of Copenhagen University, Juliane Maries Vej 30, 2100 Copenhagen Ø, Denmark M. Mandea Helmholtz-Zentrum Potsdam Deutsches GeoForschungsZentrum, 14473 Potsdam, Germany Present address: M. Mandea Equipe de Géophysique Spatiale et Planétaire, Institut de Physique du Globe de Paris (Institut de recherche associé au CNRS et à l’Université Paris 7), Bâtiment Lamarck, 5 rue Thomas Mann, 75013 Paris, France