D. W. Allan and E. C. Bullard, The secular variation of the earth's magnetic field, Proc. Cambridge Philos. Soc, pp.783-80910, 1966.
DOI : 10.1098/rsta.1954.0018

H. Amit and U. R. Christensen, Accounting for magnetic diffusion in core flow inversions from geomagnetic secular variation, Geophys, J. Int, vol.175, pp.913-924, 2008.

H. Amit, P. Olson, and U. R. Christensen, Tests of core flow imaging methods with numerical dynamos, Geophys, J. Int, vol.168, pp.27-39, 2007.

J. Aubert, J. Aurnou, and J. Wicht, The magnetic structure of convection-driven numerical dynamos, Geophysical Journal International, vol.172, issue.3, pp.945-956, 2008.
DOI : 10.1111/j.1365-246X.2007.03693.x
URL : https://hal.archives-ouvertes.fr/hal-00365069

G. E. Backus, Kinematics of Geomagnetic Secular Variation in a Perfectly Conducting Core, Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences, vol.263, issue.1141, pp.239-266, 1968.
DOI : 10.1098/rsta.1968.0014

J. Bloxham, The expulsion of magnetic flux from the Earth's core, Geophysical Journal International, vol.87, issue.2, pp.669-678, 1986.
DOI : 10.1111/j.1365-246X.1986.tb06643.x

J. Bloxham and D. Gubbins, The secular variation of Earth's magnetic field, Nature, vol.313, issue.6040, pp.777-78110, 1038.
DOI : 10.1038/317777a0

J. Bloxham and D. Gubbins, Geomagnetic field analysis-IV. Testing the frozen-flux hypothesis, Geophysical Journal International, vol.84, issue.1, pp.139-152, 1986.
DOI : 10.1111/j.1365-246X.1986.tb04349.x

J. Bloxham and A. Jackson, Fluid flow near the surface of Earth's outer core, Reviews of Geophysics, vol.94, issue.2, pp.97-120, 1991.
DOI : 10.1029/90RG02470

J. Bloxham, D. Gubbins, and A. Jackson, Geomagnetic Secular Variation, Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences, vol.329, issue.1606, pp.415-502, 1989.
DOI : 10.1098/rsta.1989.0087

S. I. Braginsky and P. H. Roberts, Equations governing convection in earth's core and the geodynamo, Geophysical & Astrophysical Fluid Dynamics, vol.444, issue.1-4, pp.1-9710, 1080.
DOI : 10.1111/j.1365-246X.1961.tb06819.x

A. Chulliat, Geomagnetic secular variation generated by a tangentially geostrophic flow under the frozen-flux assumption-II. Sufficient conditions, Geophysical Journal International, vol.157, issue.2, pp.537-552, 2004.
DOI : 10.1111/j.1365-246X.2004.02216.x

A. Chulliat and G. Hulot, Geomagnetic secular variation generated by a tangentially geostrophic flow under the frozen?flux assumption?I. Necessary conditions, Geophys, J. Int, vol.147, pp.237-246, 2001.

C. G. Constable, R. L. Parker, and P. Stark, Geomagnetic field models incorporating frozen-flux constraints, Geophysical Journal International, vol.113, issue.2, pp.419-433, 1993.
DOI : 10.1111/j.1365-246X.1993.tb00897.x

S. J. Drew, Magnetic field expulsion into a conducting mantle, Geophysical Journal International, vol.115, issue.1, pp.303-312, 1993.
DOI : 10.1111/j.1365-246X.1993.tb05604.x

E. Friis?christensen, H. Lühr, and G. Hulot, Swarm: A constellation to study the Earth???s magnetic field, Earth, Planets and Space, vol.388, issue.2, pp.351-358, 2006.
DOI : 10.1186/BF03351933

D. Gubbins, Mechanism for geomagnetic polarity reversals, Nature, vol.326, issue.6109, pp.167-169, 1987.
DOI : 10.1038/326167a0

D. Gubbins, A formalism for the inversion of geomagnetic data for core motions with diffusion, Physics of the Earth and Planetary Interiors, vol.98, issue.3-4, pp.193-20610, 1996.
DOI : 10.1016/S0031-9201(96)03187-1

D. Gubbins, Geomagnetic constraints on stratification at the top of the Earth's core, Earth Planets Space, pp.661-664, 2007.

D. Gubbins and P. Kelly, A difficulty with using the Frozen Flux Hypothesis to find steady core motions, Geophysical Research Letters, vol.122, issue.14, pp.1825-182810, 1996.
DOI : 10.1029/96GL01392

D. Gubbins and P. H. Roberts, Magnetohydrodynamics of the Earth's core, Geomagnetism, pp.1-183, 1987.

D. Gubbins, A. L. Jones, and C. C. Finlay, Fall in Earth's Magnetic Field Is Erratic, Science, vol.312, issue.5775, pp.900-902, 2006.
DOI : 10.1126/science.1124855

R. Hide, How to locate the electrically conducting fluid core of a planet from external magnetic observations, Nature, vol.271, issue.5646, pp.640-64110, 1038.
DOI : 10.1038/271640a0

R. Holme and N. Olsen, Core surface flow modelling from high-resolution secular variation, Geophysical Journal International, vol.166, issue.2, pp.518-528, 2006.
DOI : 10.1111/j.1365-246X.2006.03033.x

G. Hulot and A. Chulliat, On the possibility of quantifying diffusion and horizontal Lorentz forces at the Earth???s core surface, Physics of the Earth and Planetary Interiors, vol.135, issue.1, pp.47-5410, 2003.
DOI : 10.1016/S0031-9201(02)00191-7

G. Hulot, C. Eymin, B. Langlais, M. Mandea, and N. Olsen, Small-scale structure of the geodynamo inferred from Oersted and Magsat satellite data, Nature, vol.416, issue.6881, pp.620-62310, 2002.
DOI : 10.1038/416620a

A. Jackson, The Earth's magnetic field at the core?mantle boundary, 1989.

A. Jackson and C. C. Finlay, Geomagnetic Secular Variation and Its Applications to the Core, Treatise of Geophysics, pp.147-193, 2007.
DOI : 10.1016/B978-044452748-6/00090-0

A. Jackson, C. G. Constable, M. R. Walker, and R. L. Parker, Models of Earth's main magnetic field incorporating flux and radial vorticity constraints, THE CORE B05105 B05105 straints, pp.133-144, 2007.
DOI : 10.1111/j.1365-246X.2007.03526.x

D. Jault and J. ?. , Physical properties at the top of the core and core surface motions, Physics of the Earth and Planetary Interiors, vol.68, issue.1-2, pp.76-8410, 1991.
DOI : 10.1016/0031-9201(91)90009-7

L. Mouël and J. ?. , Outer-core geostrophic flow and secular variation of Earth's geomagnetic field, Nature, vol.73, issue.5988, pp.734-73510, 1038.
DOI : 10.1038/311734a0

J. J. Love, A critique of frozen-flux inverse modelling of a nearly steady geodynamo, Geophysical Journal International, vol.138, issue.2, pp.353-365, 1999.
DOI : 10.1046/j.1365-246x.1999.00895.x

F. Lowes, Mean-square values on sphere of spherical harmonic vector fields, Journal of Geophysical Research, vol.71, issue.8, pp.10-1029, 1966.
DOI : 10.1029/JZ071i008p02179

S. Maus, On the applicability of the frozen flux approximation in core flow modelling as a function of temporal frequency and spatial degree, Geophysical Journal International, vol.175, issue.3, pp.853-856, 2008.
DOI : 10.1111/j.1365-246X.2008.03972.x

S. Maus and P. Weidelt, Separating the magnetospheric disturbance magnetic field into external and transient internal contributions using a 1D conductivity model of the Earth, Geophysical Research Letters, vol.30, issue.4, pp.10-1029, 2004.
DOI : 10.1029/2004GL020232

S. Maus, H. Lühr, M. Rother, K. Hemant, G. Balasis et al., Fifth-generation lithospheric magnetic field model from CHAMP satellite measurements, Geochemistry, Geophysics, Geosystems, vol.299, issue.4, pp.10-1029, 2007.
DOI : 10.1029/2006GC001521

O. 'brien, M. S. , C. G. Constable, and R. L. Parker, Frozen-flux modelling for epochs 1915 and 1980, Geophysical Journal International, vol.128, issue.2, pp.434-450, 1915.
DOI : 10.1111/j.1365-246X.1997.tb01566.x

N. Olsen, A model of the geomagnetic field and its secular variation for epoch 2000 estimated from ??rsted data, Geophysical Journal International, vol.149, issue.2, pp.454-462, 2002.
DOI : 10.1046/j.1365-246X.2002.01657.x

N. Olsen, T. J. Sabaka, and F. Lowes, New parameterization of external and induced fields in geomagnetic field modeling, and a candidate model for IGRF 2005, Earth, Planets and Space, vol.30, issue.12, pp.1141-1149, 2005.
DOI : 10.1186/BF03351897

N. Olsen, H. Lühr, T. J. Sabaka, M. Mandea, M. Rother et al., CHAOS-a model of the Earth's magnetic field derived from CHAMP, ??rsted, and SAC-C magnetic satellite data, Geophysical Journal International, vol.166, issue.1, pp.67-75, 2006.
DOI : 10.1111/j.1365-246X.2006.02959.x

P. Olson and H. Amit, Changes in earth???s dipole, Naturwissenschaften, vol.128, issue.2, pp.519-54210, 2006.
DOI : 10.1007/s00114-006-0138-6

S. Rau, U. Christensen, A. Jackson, and J. Wicht, Core flow inversion tested with numerical dynamo models, Geophys, J. Int, vol.141, pp.485-497, 2000.

P. H. Roberts and G. A. Glatzmaier, A test of the frozen-flux approximation using a new geodynamo model, Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences, vol.358, issue.1768, pp.1109-1121, 2000.
DOI : 10.1098/rsta.2000.0576

P. H. Roberts and S. Scott, On Analysis of the Secular Variation, Journal of geomagnetism and geoelectricity, vol.17, issue.2, pp.137-151, 1965.
DOI : 10.5636/jgg.17.137

T. J. Sabaka, N. Olsen, and M. Purucker, Extending comprehensive models of the Earth's magnetic field with ??rsted and CHAMP data, Geophysical Journal International, vol.159, issue.2, pp.521-547, 2004.
DOI : 10.1111/j.1365-246X.2004.02421.x

L. Shure, R. L. Parker, and G. Backus, Harmonic splines for geomagnetic modelling, Physics of the Earth and Planetary Interiors, vol.28, issue.3, pp.215-22910, 1982.
DOI : 10.1016/0031-9201(82)90003-6

F. Takahashi, M. Matsushima, and Y. Honkura, Simulations of a Quasi-Taylor State Geomagnetic Field Including Polarity Reversals on the Earth Simulator, Science, vol.309, issue.5733, pp.459-461, 2005.
DOI : 10.1126/science.1111831

I. Wardinski and R. Holme, A time?dependent model of the Earth's magnetic field and its secular variation for the period, J. Geophys. Res, pp.10-1029, 1980.

K. Whaler, Core motions, in Encyclopedia of Geomagnetism and Paleomagnetism, pp.84-89, 2007.