J. Aubert, Geomagnetic acceleration and rapid hydromagnetic wave dynamics in advanced numerical simulations of the geodynamo, Geophys J Int, vol.214, pp.531-547, 2018.

G. Balasis and G. D. Egbert, Empirical orthogonal function analysis of magnetic observatory data: further evidence for non-axisymmetric magnetospheric sources for satellite induction studies, Geophys Res Lett, vol.33, p.11311, 2006.

O. Barrois, M. D. Hammer, C. C. Finlay, Y. Martin, and N. Gillet, Assimilation of ground and satellite magnetic measurements: inference of core surface magnetic and velocity field changes, Geophys J Int, vol.215, pp.695-712, 2018.

J. Bartels, The eccentric dipole approximating the earth's magnetic field, Terr Mag Atmos Elect, vol.41, pp.225-250, 1936.

C. D. Beggan and K. A. Whaler, Ensemble Kalman filter analysis of magnetic field models during the CHAMP-Swarm gap, Phys Earth Planet Inter, vol.281, pp.103-110, 2018.

C. D. Beggan, K. A. Whaler, and S. Macmillan, Biased residuals of core flow models from satellite-derived 'virtual observatories', Geophys J Int, vol.177, pp.463-475, 2009.

U. R. Christensen and A. J. , Scaling properties of convection-driven dynamos in rotating spherical shells and application to planetary magnetic fields, Geophys J Int, vol.166, pp.97-114, 2006.
URL : https://hal.archives-ouvertes.fr/hal-00149194

U. R. Christensen, I. Wardinski, and V. Lesur, Timescales of geomagnetic secular acceleration in satellite field models and geodynamo models, Geophys J Int, vol.190, pp.243-254, 2012.

A. Chulliat and S. Maus, Geomagnetic secular acceleration, jerks, and a localized standing wave at the core surface from 2000 to 2010, J Geophys Res Solid Earth, vol.119, pp.1531-1543, 2014.

A. Chulliat, P. Alken, and S. Maus, Fast equatorial waves propagating at the top of the Earth's core, Geophys Res Lett, vol.42, pp.3321-3329, 2015.

G. Cox, P. W. Livermore, and J. Mound, The observational signature of modelled torsional waves and comparison to geomagnetic jerks, Phys Earth Planet Inter, vol.255, pp.50-65, 2016.

D. Santis, A. Barraclough, D. R. Tozzi, and R. , Spatial and temporal spectra of the geomagnetic field and their scaling properties, Phys Earth Planet Inter, vol.135, pp.125-134, 2003.

J. Domingos, D. Jault, M. A. Pais, and M. Mandea, The South Atlantic Anomaly throughout the solar cycle, Earth Planet Sci Lett, vol.473, pp.154-163, 2017.

D. Dommenget, Evaluating EOF modes against a stochastic null hypothesis, Clim Dyn, vol.28, pp.517-531, 2007.

C. C. Finlay, N. Olsen, N. Kotsiaros, N. Gillet, and L. Tøffner-clausen, Recent geomagnetic secular variation from Swarm and ground observatories as estimated in the CHAOS-6 geomagnetic field model, Earth Planets Space, vol.68, p.112, 2016.

A. C. Fraser-smith, Centered and eccentric geomagnetic dipoles and their poles, 1600-1985, Rev Geophys, vol.25, pp.1-16, 1987.

J. F. Gibson, D. Farmer, J. Casdagli, M. Eubank, and S. , An analytic approach to practical state space reconstruction, Physica D, vol.57, pp.1-30, 1992.

N. Gillet, Spatial and temporal changes of the geomagnetic field: insights from forward and inverse core field models, Geomagnetism, vol.9, 2018.
URL : https://hal.archives-ouvertes.fr/hal-02042703

N. Gillet, D. Jault, E. Canet, and A. Fournier, Fast torsional waves and strong magnetic field within the Earth's core, Nature, vol.465, pp.74-77, 2010.

A. Hannachi, I. T. Jolliffe, and D. B. Stephenson, Empirical orthogonal functions and related techniques in atmospheric science: a review, Int J Climatol, vol.27, pp.1119-1152, 2007.

G. Hellio, N. Gillet, C. Bouligand, and D. Jault, Stochastic modelling of regional archaeomagnetic series, Geophys J Int, vol.199, pp.931-943, 2014.
URL : https://hal.archives-ouvertes.fr/hal-01138124

G. Hulot, L. Mouël, and J. , A statistical approach to the Earth's main magnetic field, Phys Earth Planet Inter, vol.82, pp.167-183, 1994.

R. James and D. E. Winch, The eccentric dipole, Pure Appl Geophys, vol.66, pp.77-86, 1967.

I. T. Jolliffe, R. A. Langel, D. J. Kerridge, D. R. Barraclough, and S. Malin, Geomagnetic temporal change: 1903-1982, a spline representation, J Geomag Geoelectr, vol.38, pp.573-597, 1986.

K. Laundal and A. D. Richmond, Magnetic coordinate systems, Space Sci Rev, vol.206, issue.1-4, pp.27-59, 2017.

P. Leopardi, A partition of the unit sphere into regions of equal area and small diameter, Electron Trans Numer Anal, vol.25, pp.309-327, 2006.

V. Lesur, I. Wardinski, M. Rother, and M. Mandea, GRIMM: the GFZ Reference Internal Magnetic Model based on vector satellite and observatory data, Geophys J Int, vol.173, pp.382-394, 2008.

V. Lesur, I. Wardinski, M. Hamoudi, and M. Rother, The second generation of the GFZ Reference Internal Magnetic Model, Earth Planets Space, vol.62, pp.765-773, 2010.

V. Lesur, I. Wardinski, J. Baerenzung, and M. Holschneider, On the frequency spectra of the core magnetic field Gauss coefficients, Phys Earth Planet Inter, vol.276, pp.145-158, 2018.

F. Lhuillier, A. Fournier, G. Hulot, and A. J. , The geomagnetic secularvariation timescale in observations and numerical dynamo models, Geophys Res Lett, vol.38, p.9306, 2011.
URL : https://hal.archives-ouvertes.fr/insu-01410184

P. W. Livermore, R. Hollerbach, and C. C. Finlay, An accelerating high-latitude jet in Earth's core, Nat Geosci, vol.10, pp.62-68, 2017.

F. J. Lowes, The geomagnetic eccentric dipole: fact and fallacies, Geophys J Int, vol.118, pp.671-679, 1994.

S. Malin and A. M. Isikara, Annual variation of the geomagnetic field, Geophys J R Astron Soc, vol.47, pp.445-457, 1976.

M. Mandea and N. Olsen, A new approach to directly determine the secular variation from magnetic satellite observations, Geophys Res Lett, vol.33, p.15306, 2006.

K. A. Mckinnon, A. Rhines, M. P. Tingley, and P. Huybers, The changing shape of Northern Hemisphere summer temperature distributions, J Geophys Res Atmos, vol.121, pp.8849-8868, 2016.

H. C. Nataf and N. Schaeffer, Oxford North GR, Bell TL, Cahalan RF, Moeng FJ (1982) Sampling errors in the estimation of empirical orthogonal functions, Turbulence in the core. In: Schubert G (ed) Treatise on geophysics, vol.8, pp.699-706, 2015.

N. Olsen and M. Mandea, Investigation of a secular variation impulse using satellite data: the 2003 geomagnetic jerk, Earth Planet Sci Lett, vol.255, pp.94-105, 2007.

M. A. Pais, A. P. Pinheiro, and F. , Time-correlated patterns from spherical harmonic expansions: application to geomagnetism, J Geophys Res Solid Earth, vol.120, pp.8012-8030, 2015.

M. A. Pais, A. L. Morozova, and N. Schaeffer, Variability modes in core flows inverted from geomagnetic field models, Geophys J Int, vol.200, pp.402-420, 2015.
URL : https://hal.archives-ouvertes.fr/insu-01009677

T. J. Sabaka, N. Olsen, and E. Purucker, Extending comprehensive models of the Earth's magnetic field with Ørsted and CHAMP data, Geophys J Int, vol.159, pp.521-547, 2004.

T. J. Sabaka, G. Hulot, and N. Olsen, Mathematical properties relevant to geomagnetic field modeling, 2010.

, Handbook of geomathematics, chapter 43, pp.503-538

D. Saturnino, B. Langlais, H. Amit, F. Civet, M. Mandea et al., Combining virtual observatory and equivalent source dipole approaches to describe the geomagnetic field with Swarm measurements, Phys Earth Planet Inter, vol.276, pp.118-133, 2018.
URL : https://hal.archives-ouvertes.fr/hal-02176349

A. Schmidt, Der magnetische Mittelpunk der Erde und seine Bedeutung, Gerlands Beitr Geophys, vol.41, pp.346-358, 1934.

R. M. Shore, K. A. Whaler, S. Macmillan, C. Beggan, J. Velímský et al., Decadal period external magnetic field variations determined via eigenanalysis, J Geophys Res Space Phys, vol.121, pp.5172-5184, 2016.

L. Silva, L. Jackson, and J. Mound, Assessing the importance and expression of the 6 year geomagnetic oscillation, J Geophys Res Solid Earth, vol.117, p.10101, 2012.

K. Taira, S. L. Brunton, S. Dawson, C. W. Rowley, T. Colonius et al., Modal analysis of fluid flows: an overview, AIAA J, vol.55, pp.4013-4041, 2017.

E. Thébault, C. C. Finlay, C. D. Beggan, P. Alken, A. J. Barrois et al., Geomagnetic Reference Field: the 12th generation, vol.67, p.79, 2015.

N. A. Tsyganenko and M. I. Sitnov, Modeling the dynamics of the inner magnetosphere during strong geomagnetic storms, J Geophys Res Space Phys, vol.110, p.3208, 2005.