International Geomagnetic Reference Field: the thirteenth generation
Patrick Alken, Erwan Thébault, Ciarán Beggan, Hagay Amit, Julien Aubert, Julien Baerenzung, T. N. Bondar, William Brown, S. Califf, Aude Chambodut, Arnaud Chulliat, Grace Cox, Christopher C. Finlay, Alexandre Fournier, Nicolas Gillet, Alexander Grayver, Magnus Hammer, M. Holschneider, Loïc Huder, Gauthier Hulot, Thomas Jäger, Clemens Kloss, Monika Korte, Weijia Kuang, Alexey Kuvshinov, B. Langlais, Jean‐Michel Léger, Vincent Lesur, Philip W. Livermore, F. J. Lowes, Susan Macmillan, W. Magnes, Mioara Mandéa, Santiago Marsal, Jürgen Matzka, Maurits C. Metman, Takuto Minami, A. Morschhauser, J. E. Mound, Manoj Nair, S. Nakano, Nils Olsen, Fco. Javier Pavón–Carrasco, V. G. Petrov, Guillaume Ropp, M. Rother, Terence J. Sabaka, Sabrina Sanchez, Diana Saturnino, N. R. Schnepf, Xiang Shen, Claudia Stolle, Andrew Tangborn, Lars Tøffner‐Clausen, Hiroaki Toh, J. M. Torta, J. D. Varner, Foteini Vervelidou, P. Vigneron, I. Wardinski, Johannes Wicht, Adam Woods, Yanyan Yang, Z. Zeren, Bin Zhou
Abstract
Abstract In December 2019, the International Association of Geomagnetism and Aeronomy (IAGA) Division V Working Group (V-MOD) adopted the thirteenth generation of the International Geomagnetic Reference Field (IGRF). This IGRF updates the previous generation with a definitive main field model for epoch 2015.0, a main field model for epoch 2020.0, and a predictive linear secular variation for 2020.0 to 2025.0. This letter provides the equations defining the IGRF, the spherical harmonic coefficients for this thirteenth generation model, maps of magnetic declination, inclination and total field intensity for the epoch 2020.0, and maps of their predicted rate of change for the 2020.0 to 2025.0 time period.