TERRAPUB Earth, Planets and Space

Earth Planets Space, Vol. 62 (No. 10), pp. 745-751, 2010

Candidate models for the IGRF-11th generation making use of extrapolated observatory data

Aude Chambodut1, Benoit Langlais2, Michel Menvielle3,4, Erwan Thébault5, Arnaud Chulliat5, and Gauthier Hulot5

1Institut de Physique du Globe de Strasbourg (UMR 7516-CNRS, Université de Strasbourg/EOST), Strasbourg, France
2Laboratoire de Planétologie et Géodynamique de Nantes (UMR 6112-CNRS, Université de Nantes), Nantes, France
3Université Versailles-St Quentin; CNRS/INSU, LATMOS-IPSL, Paris, France
4Département des Scinces de la Terre, Univ. Paris Sud, Orsay, France
5Institut de Physique du Globe de Paris, équipe de Géomagnétisme (UMR 7154-CNRS, Université Paris Diderot), Paris, France

(Received December 8, 2009; Revised June 20, 2010; Accepted June 22, 2010; Online published December 31, 2010)

Abstract: Three candidate models are produced in response to the call for IGRF-11 models. A main field model around epoch 2005.0 is based on one year of ørsted and CHAMP measurements, and is proposed for the definitive model for epoch 2005.0. A main field model around epoch 2009.5, based on two months of CHAMP measurements and extrapolated to 2010.0, is proposed as a main field model for epoch 2010.0. A secular variation model valid for 2010.0-2015.0, based on the extrapolation through exponential smoothing of observatory monthly mean values, is proposed as a predictive secular variation model. Comparison of similar extrapolations made for previous IGRF generations with actual observations are presented and discussed.
Key words: Magnetic field, main field, secular variation, modeling, IGRF, time extrapolation.

Corresponding author E-mail: aude.chambodut@eost.u-strasbg.fr

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