Publications
-2024-
(91) Finlay, C.C., J. Velímský, C. Kloss, and R.M. Blangsbøll (2024) Satellite monitoring of long period ocean-induced magnetic field variations, Phil. Trans. R. Soc. A. 38220240077 http://doi.org/10.1098/rsta.2024.0077
(90) Grayver, A., Finlay, C.C., and Olsen, N. (2024) Magnetic signals from oceanic tides: new satellite observations and applications, Phil. Trans. R. Soc. A.38220240078 http://doi.org/10.1098/rsta.2024.0078
(89) Jiang, Y., Finlay, C.C., Olsen, N., Tøffner-Clausen, L., Yan, Q., and Zhang, K. (2024) Macau Scientific Satellite-1 Initial Magnetic Field Model, Geophysical Research Letters, 51, e2024GL112305. https://doi.org/10.1029/2024GL112305
(88) Otzen, M., Finlay, C.C., Kloss, C. (2024) Co-estimation of core and lithospheric magnetic fields by a maximum entropy method, Geophys. J. Int, 236, 1646–1667, doi: https://doi.org/10.1093/gji/ggae008
(87) Barrois, O., Gastine, T. and Finlay, C.C., (2024) Quasi-geostrophic convection-driven dynamos in a thick spherical shell, Geophys. J. Int, 236, 1737–1389, doi:10.1093/gji/ggad478
-2023-
(86) Kloss, C., Finlay, C.C.,, Laundal, K.M. and Olsen, N. (2023) Polar ionospheric currents and high temporal resolution geomagnetic field models, Geophys. J. Int, 235, 1736–1760, doi: 10.1093/gji/ggad325
(85) Finlay, C.C., Gillet, N., Aubert, J., Livermore, P.W., and Jault, D. (2023) Gyres, jets and waves in the Earth's core, Nat Rev Earth Environ, doi:10.1038/s43017-023-00425-w
(84) Istas, M., Gillet, N., Finlay, C.C., Hammer, M.D., and Huder, L. (2023) Transient core surface dynamics from ground and satellite geomagnetic data, Geophys. J. Int, 233, 1890-1915, doi: 10.1093/gji/ggad039
-2022-
(83) Blangsbøll, R.M., Finlay, C.C., and Kloss, C. (2022) Localized Origin at the Core-Mantle Boundary of the 1969 Geomagnetic Impulse, Geophys. Res. Lett, e2022GL101070, doi: 10.1029/2022GL101070
(82) Hansen, T.M. and Finlay, C.C. (2022) Use of Machine Learning to Estimate Statistics of the Posterior Distribution in Probabilistic Inverse Problems — An Application to Airborne EM Data, Journal of Geophysical Research: Solid Earth, 127, e2022JB024703, doi:10.1029/2022JB024703
(81) Whaler, K.A., Hammer, M.D., Finlay, C.C., and Olsen, N. (2022) Core surface flow changes associated with the 2017 Pacific geomagnetic jerk, Geophys. Res. Lett, 49, 15, doi: 10.1029/2022GL098616
(80) Aubert, J., Livermore, P.W., Finlay, C.C., Fournier, A. and Gillet, N. (2022) A taxonomy of simulated geomagnetic jerks, Geophys. J. Int, 229, 129–158, doi: 10.1093/gji/ggac212
(79) Barrois, O., Gastine, T. and Finlay, C.C. (2022) Comparison of quasi-geostrophic, hybrid and 3-D models of planetary core convection, Geophys. J. Int, 229, 129–158, doi: 10.1093/gji/ggac141
(78) Hammer, M. D., Finlay, C.C. and Olsen, N. (2022) Secular variation signals in magnetic field gradient tensor elements derived from satellite-based geomagnetic virtual observatories, Geophys. J. Int, 229, 2096–2114, doi: 10.1093/gji/ggac004
(77) Otzen, M.,Finlay, C.C. and Hansen, T.M. (2022) Direct Sequential Simulation for spherical linear inverse problems, Computers & Geosciences, 160:105026, doi: 10.1016/j.cageo.2021.105026
-2021-
(76) Hammer, M.D. Finlay, C.C. and Olsen, N. (2021) Applications for CryoSat‑2 satellite magnetic data in studies of Earth’s core field variations Earth, Planets, Space, 73:73, doi:10.1186/s40623-021-01365-9
(75) Hammer, M.D., Cox, G.A., Brown, W.J., Beggan, C.D. and Finlay, C.C. (2021) Geomagnetic Virtual Observatories: monitoring geomagnetic secular variation with the Swarm satellites Earth, Planets, Space, 73:54, doi: 10.1186/s40623-021-01357-9
(74) Kloss, C., Finlay, C.C. and Olsen, N. (2021) Co-estimating geomagnetic field and calibration parameters: modeling Earth’s magnetic field with platform magnetometer data Earth, Planets, Space, 73:23, doi: 10.1186/s40623-020-01351-7
(73) Alken, P. et al. (2021b) Evaluation of candidate models for the 13th generation International Geomagnetic Reference Field Earth, Planets, Space, 73:48, doi:10.1186/s40623-020-01281-4
(72) Alken, P. et al. (2021a) International Geomagnetic Reference Field: the thirteenth generation Earth, Planets, Space, 73:49, doi:10.1186/s40623-020-01288-x
-2020-
(71) Finlay, C.C. Kloss, C., Olsen, N., Hammer, M.D., Tøffner-Clausen, L., Grayver, A. and Kuvshinov, A. (2020) The CHAOS‑7 geomagnetic field model and observed changes in the South Atlantic Anomaly Earth, Planets, Space, 72:156, doi: 10.1186/s40623-020-01252-9
(70) Laundal, K.M., Reistad, J.P., Hatch, S.M., Moretto, T., Ohma, A., Østergaard, N., Tenfjord, P.A.R., Finlay, C.C. and Kloss, C.(2020) Time‑scale dependence of solar wind‑based regression models of ionospheric electrodynamics Sci. Rep. 10, 16406, doi:10.1038/s41598-020-73532-z
(69) Huder, L., Gillet, N., Finlay, C.C. , Hammer, M.D. and Tchoungui, H. (2020) COV‑OBS.x2: 180 years of geomagnetic field evolution from ground‑based and satelliteobservations Earth, Planets, Space, 72:160, doi: 10.1186/s40623-020-01194-2
(68) Sabaka, T.J., Tøffner-Clausen, L., Olsen, N. and Finlay, C.C. (2020) CM6: a comprehensive geomagnetic field model derived from both CHAMP and Swarm satellite observations, Earth, Planets, Space, 72:80, doi:10.1186/s40623-020-01210-5
(67) Troyano, M., Fournier, A., Gallet, Y. and Finlay, C.C. (2020) Imprint of magnetic flux expulsion at the core–mantle boundary on geomagnetic field intensity variations Geophys. J. Int., 221, Issue 3, 1984–2009.
(66) Livermore, P.W., Finlay, C.C. and Bayliff, M. (2020) Recent north magnetic pole acceleration towards Siberia caused by flux lobe elongation, Nature Geoscience, 13, 387–391
(65) Alken, P., Olsen, N. and Finlay, C.C. (2020) Co‑estimation of geomagnetic field and in‑orbit fluxgate magnetometer calibration parameters, Earth, Planets, Space, 72:49, 1-32.
(64) Finlay, C.C. (2020) Models of the Main Geomagnetic Field Based on Multi-satellite Magnetic Data and Gradients—Techniques and Latest Results from the Swarm Missions, Ionospheric Multi-Spacecraft Analysis Tools, ISSI Scientific Report Series 17, 255-284
-2019-
(63) Aubert, J. and Finlay, C.C. (2019) Geomagnetic jerks and rapid hydromagnetic waves focusing at Earth’s core surface, Nature Geoscience, Vol 12, Issue 4, DOI:10.1038/s41561-019-0355-1
(62) Kloss, C. and Finlay, C.C. (2019) Time-dependent low-latitude core flow and geomagnetic field acceleration pulses, Geophys. J. Int., Vol 217, 140-168.
(61) Hammer, M. D. and Finlay, C.C. (2019) Local averages of the core–mantle boundary magnetic field from satellite observations, Geophys. J. Int., Vol 216, 1901-1918
-2018-
(60) Sheyko, A., Finlay, C.C., Favre, J., and Jackson, A. (2018) Scale separated low viscosity dynamos and dissipation within the Earth’s core, Scientific Reports, Vol 8, 12566, DOI:10.1038/s41598-018-30864-1
(59) Barrois, O., Hammer, M.D., Finlay, C.C., Martin, Y., and Gillet, N. (2018) Assimilation of ground and satellite magnetic measurements: inference of core surface magnetic and velocity field changes, Geophys. J. Int, Vol 215, 695-712, doi:10.1093/gji/ggy297
(58) Sabaka, T.J., Toeffner-Clausen, L., Olsen, N. and Finlay, C.C. (2018) A comprehensive model of Earth’s magnetic field determined from 4 years of Swarm satellite observations, Earth, Planets, Space, Vol 70, 130, https://doi.org/10.1186/s40623-018-0896-3
(57) Laundal, K. M., Finlay, C.C., Olsen, N., and Reistad, J.P (2018) Solar Wind and Seasonal Influence on Ionospheric Currents From Swarm and CHAMP Measurements, J. Geophys. Res., Space Physics, Vol 123, https://doi.org/10.1029/2018JA025387
(56) Laundal, K. M., Reistad, J.P., Finlay, C.C., Ostergaard, N., Tenfjord, P., Snekvik, K. and Ohma, A. (2018) Interplanetary Magnetic Field B_x Component Influence on Horizontal and Field-Aligned Currents in the Ionosphere, J. Geophys. Res., Space Physics, Vol 123, https://doi.org/10.1002/2017JA024864
-2017-
(55) Olsen, N., Ravat, D., Finlay, C.C., and Kother, L.K. (2017) LCS-1: a high-resolution global model of the lithospheric magnetic field derived from CHAMP and Swarm satellite observations, Geophys. J. Int., Vol 221, Pages 1461–1477, doi:10.1093/gji/ggx381.
(54) Ou, J., Du, A. and Finlay, C.C. (2017) Quasi-biennial oscillations in the geomagnetic field: Their global characteristics and origin, J. Geophys. Res., Space Physics, Vol 122, doi:10.1002/2016JA023292.
(53) Herland, E. V., Finlay, C.C., Olsen, N., Edvardsen, I. Nordgaard-Hansen, E., Laundal, K. M. and Waag, T. I. (2017) The CHAOS-X Model and Uncertainty Values for Magnetic Directional Surveying, SPE Bergen One Day Seminar, doi:10.2118/185895-MS
(52) Friis-Christensen, E., Finlay, C.C., Hesse, M. and Laundal, K.M. (2017) Magnetic Field Perturbations from Currents in the Dark Polar Regions During Quiet Geomagnetic Conditions, Space Sci Rev, doi:10.1007/s11214-017-0332-1
(51) Kauristie, K., Morschhauser, A., Olsen, N., Finlay, C.C., McPherron, R.L., Gjerloev, J.W., Opgenoorth, H.J. (2017) On the Usage of Geomagnetic Indices for Data Selection in Internal Field Modelling, Space Science Reviews, doi:10.1007/s11214-016-0301-0
(50) Finlay, C.C., Lesur, V., Thebault, E., Vervelidou, F., Morschhauser, A. and Shore, R. (2017) Challenges Handling Magnetospheric and Ionospheric Signals in Internal Geomagnetic Field Modelling, Space Science Reviews, doi:10.1007/s11214-016-0285-9
(49) Livermore, P.W., Hollerbach, R. and Finlay, C.C. (2017) An accelerating high-latitude jet in Earth’s core, Nature Geoscience, 10, 62-68, doi:10.1038/ngeo2859
-2016-
(48) Sheyko, A., Finlay, C.C. and Jackson A. (2016) Magnetic reversals from planetary dynamo waves, Nature, 539, 551–554, doi:10.1038/nature19842
Reversal movie on youtube
(47) Laundal, K. M., Finlay, C.C., and Olsen, N. (2016) Sunlight effects on the 3D polar current system determined from low Earth orbit measurements, Earth Planets Space, Vol 68, 142 doi: 10.1186/s40623-016-0518-x
(46) Whaler, K. A., Olsen, N., and Finlay, C.C. (2016) Decadal variability in core surface flows deduced from geomagnetic observatory monthly means, Geophys. J. Int., Vol 207, 228-243, doi: 10.1093/gji/ggw268
(45) Drost Aakjaer, C., Olsen, N., and Finlay, C.C. (2016) Determining polar ionospheric electrojet currents from Swarm satellite constellation magnetic data, Earth Planets Space, Vol 68, 140, doi: 10.1186/s40623-016-0509-y
(44) Olsen, N., Finlay, C.C., Kotsiaros, S. and Toeffner-Clausen, L. (2016) A model of Earth's magnetic field derived from two years of Swarm satellite constellation data, Earth Planets Space, Vol 68, 124, doi: 10.1186/s40623-016-0488-z
(43) Toeffner-Clausen, L., Lesur, V., Olsen, N. and Finlay, C.C. (2016) In-flight scalar calibration and characterisation of the Swarm magnetometry package, Earth Planets Space, Vol 68, 129, doi: 10.1186/s40623-016-0501-6
(42) Finlay, C.C., Olsen, N., Kotsiaros, S., Gillet, N. and Toeffner-Clausen, L. (2016) Recent geomagnetic secular variation from Swarm and ground observatories as estimated in the CHAOS-6 geomagnetic field model, Earth Planets Space, Vol 68, 112. doi: 10.1186/s40623-016-0486-1
(41) Finlay, C.C., Aubert, J. and Gillet, N. (2016) Gyre-driven decay of the Earth's magnetic dipole, Nature Comm., Vol 7, doi: 10.1038/ncomms10422
-2015-
(40) Torta, J.M., Pavon-Carrasco, F.J., Marsal, S., and Finlay, C.C. (2015) Evidence for a new geomagnetic jerk in 2014, Geophys. Research., Letters., Vol 42, doi: 10.1002/2015GL065501
(39) Kother, L., Hammer, M.D., Finlay, C.C. and Olsen, N. (2015) An equivalent source method for modelling the global lithospheric magnetic field, Geophys. J., Int., Vol 203, 553-566, doi: 10.1093/gji/ggv317
(38) Finlay, C.C., Olsen, N. and Toeffner-Clausen, L. (2015) DTU candidate field models for IGRF-12 and the CHAOS-5 geomagnetic field model, Earth, Planets and Space, Vol 67:114 doi:10.1186/s40623-015-0274-3
(37) Thebault, E., Finlay, C.C., Alken, P., Beggan, C.D., Canet, E., Chulliat, A., Langlais, B., Lesur, V., Lowes, F.J., Manoj, C., Rother, M., and Schachtschneider, R. (2015) Evaluation of candidate geomagnetic field models for IGRF-12,Earth, Planets and Space, Vol 67:112 doi:10.1186/s40623-015-0273-4
(36) Thebault, E., Finlay, C.C., Beggan, C.D., Alken, P. Aubert, J., Barrois, O., Bertrand, F., Bondar, T., Boness, A., Brocco, L., Canet, E. Chambodut, A., Chulliat, A., Coisson, P., Civet, F., Du, A., Fournier, A., Fratter, I., Gillet, N., Hamilton, B., Hamoudi, M., Hulot, G., Jager, T., Korte, M., Kuang, W., Lalanne, X., Langlais, B., Leger, J.M., Lesur, V., Lowes, F.J., Macmillan, S., Mandea, M., Manoj, C., Maus, S., Olsen, N., Petrov, V., Ridley, V., Rother, M., Sabaka, T.J., Saturnino, D., Schachtschneider, R., Sirol, O., Tangborn, A., Thomson, A., Toeffner-Clausen, L., Vigneron, P., Wardinski, I., and Zvereva, T., (2015) International Geomagnetic Reference Field: the 12th generation ,Earth, Planets and Space, Vol 67:79, doi:10.1186/s40623-015-0228-9
(35) Gillet, N., Barrois, O., and Finlay, C.C. (2015) Stochastic forecasting of the geomagnetic field from the COV-OBS.x1 geomagnetic field model, and candidate models for IGRF-12,Earth, Planets and Space, Vol 67:71 doi:10.1186/s40623-015-0225-z
(34) Gillet, N., Jault, D., and Finlay, C.C. (2015) Planetary gyre, time-dependent eddies, torsional waves, and equatorial jets at the Earth's core surface, J. Geophys. Res., doi: DOI: 10.1002/2014JB011786.
(33) Jault, D. and Finlay, C.C., (2015) Waves in the core and mechanical core-mantle interactions. Treatise on Geophysics, 2nd Edition, Volume 8: Core Dynamics, Volume editor P. Olson, Series editor G. Schubert, Elsevier Publishers , Chapter 8.09, 225-244.
(32) Jackson, A. and Finlay, C.C., (2015) Geomagnetic secular variation and applications to the core. Treatise on Geophysics, 2nd Edition, Volume 5: Geomagnetism, Volume editor M. Kono, Series editor G. Schubert, Elsevier Publishers , Chapter 5.05, 137-184.
(31) Panovska, S., Korte, M., Finlay, C.C., and Constable, C.G., (2015) Limitations in paleomagnetic data and modelling techniques and their impact on Holocene geomagnetic field models, Geophysical Journal International, 202, doi: 10.1093/gji/ggv137.
(30) Olsen, N., Hulot, G., Lesur, V., Finlay, C.C., Beggan, C., Chulliat, A., Sabaka, T.J., Floberghagen, R., Friis-Christensen, E., Haagmans, R., Kotsiaros, S., Luehr, H., Toeffner-Clausen, L., Vigneron, P., (2015) The Swarm Initial Field Model for the 2014 geomagnetic field, Geophysical Research Letters, 42, doi:10.1002/2014GL062659.
(29) Kotsiaros, S., Finlay, C.C., Olsen, N. (2015) Use of along-track magnetic field differences in lithospheric field modelling , Geophys. J. Int., Vol 200, 880-889, doi:10.1093/gji/ggu431.
-2014-
(28) Olsen, N., Luehr, H., Finlay, C.C., Sabaka, T. J., Michaelis, I., Rauberg, J. Toeffner-Clausen, L. (2014) The CHAOS-4 geomagnetic field model, Geophys. J. Int., Vol 197, 815-827, doi: 10.1093/gji/ggu033.
(27) Canet, E., Finlay, C.C., Fournier, A. (2014) Hydromagnetic quasi-geostrophic modes in rapidly rotating planetary cores, Phys. Earth. Planet. Int., Vol 229, 1-15, .doi:10.1016/j.pepi.2013.12.006
-2013-
(26) Aubert, J., Finlay, C.C., Fournier, A. (2013) Bottom-up control of geomagnetic secular variation by the Earth's inner core, Nature, Vol 502, 219-223, doi:10.1038/nature12574.
(25) Panovska, S., Finlay, C.C., Hirt, A.M. (2013) Observed periodicities and the spectrum of field variations in Holocene magnetic records, Earth Planet. Sci. Lett., Vol 379, 88-94, doi:10.1016/j.epsl.2013.08.010.
(24) Gillet, N., Jault, D., Finlay, C.C., Olsen, N. (2013) Stochastic modeling of the Earth's magnetic field: Inversion for covariances over the observatory era, Geochemistry, Geophysics, Geosystems, Vol 14, 766-786, doi:10.1002/ggge.20041.
-2012-
(23) Finlay, C.C. (2012) Earth's eccentric magnetic field, Nature Geosci., Vol 5, 523-524, doi:10.1038/ngeo1516.
(22) Finlay, C.C., Jackson, A., Gillet, N. and Olsen, N. (2012) Core surface magnetic field evolution 2000 - 2010 , Geophys. J. Int., Vol 189, 761-781.
(21) Panovska, S., Finlay, C.C., Donadini, F., and Hirt, A. M. (2012) Spline analysis of Holocene sediment magnetic records: Uncertainty estimates for field modeling, J. Geophys. Res., Vol 117, B02101, doi:10.1029/2011JB008813.
-2011-
(20) Pinheiro, K. J., Jackson, A. and Finlay, C.C., (2011) Measurements and uncertainties of the occurrence time of the 1969, 1978, 1991, and 1999 geomagnetic jerks, Geochemisty, Geophysics, Geosystems, Vol. 12, Q10015, 32 pp. doi:10.1029/2011GC003706
(19) Finlay, C.C., and Amit, H., (2011) On flow magnitude and field-flow alignment at Earth's core surface, Geophys. J. Int., Vol 186, 175-192, doi:10.1111/j.1365-246X.2010.04804.x.
(18) Velimsky, J. and Finlay, C.C., (2011) Effect of a metallic core on transient geomagnetic induction, Geochemisty, Geophysics, Geosystems, Vol. 12, Q05011, 8 pp. doi:10.1029/2011GC003557
(17) S. Macmillan, and Finlay, C.C., (2011) The International Geomagnetic Reference Field, IAGA Special Sopron Book Series, Vol. 5, Geomagnetic Observations and Models, Ed. Mandea, M., Korte, 265-276, DOI: 10.1007/978-90-481-9858-0_10
-2010-
(16) Finlay, C.C., Maus, S., Beggan, C. D., Hamoudi, M., Lowes, F. J., Olsen, N., and Thebault. E., (2010) Evaluation of candidate geomagnetic field models for IGRF-11, Earth, Planets, Space, Vol. 62, 787-804.
(15) Finlay, C.C., Maus, S., Beggan, C. D., Bondar, T. N., Chambodut, A., Chulliat, A., Golovkov, V. P., Hamilton, B., Hamoudi, M., Holme, R., Hulot, G., Kuang, W., Langlais, B., Lesur, V., Lowes, F. J., Luehr, H., Macmillan, S. Mandea, M. McLean, S., C. Manoj, Menvielle, M., Michaelis, I. Olsen, N., Rauberg, J., Rother, M., Sabaka, T. J., Tangborn, A., Toffner-Clausen, L., Thebault, E., Thomson, A. W. P., Wardinski, I., Wei, Z., and Zvereva, T. I., (2010) International Geomagnetic Reference Field: The Eleventh Generation, Geophys. J. Int., 183, 1216-1230, doi:10.1111/j.1365-246X.2010.04804.x.
(14) Finlay, C.C., Dumberry, M. Chulliat, A., and Pais, A. M. (2010) Short timescale core dynamics: theory and observations, Space Science Reviews, 155, 177-218, DOI: 10.1007/s11214-010-9691-6.
(13) Matzka, J., Chulliat, A., Mandea, M., Finlay, C.C., Qamili, E. (2010) Geomagnetic observations for main field studies: from ground to space, Space Science Reviews, 155, 29-64, DOI: 10.1007/s11214-010-9693-4.
(12) Hulot, G., Finlay, C.C., Constable, C.G., Olsen, N. and Mandea, M. (2010) The Magnetic Field of Planet Earth, Space Science Reviews, 152, 159-222, DOI:10.1007/s11214-010-9644-0.
-2009-
(11) Stockmann, R., Finlay, C.C. and Jackson, A. (2009) Imaging Earth's crustal magnetic field with satellite data: a regularized spherical triangle tessellation approach, Geophys. J. Int. , 179, 929-944.
-2008-
(10) Finlay, C.C., (2008) Historical variation of the geomagnetic axial dipole. Phys. Earth Planet. Int. , 170, 1-14.
(9) Finlay, C.C., (2008) Waves in the Presence of Magnetic Fields, Rotation and Convection.Dynamos, Les Houches Summer School Preceedings, Session LXXVIII, Chapter 8, 407-447.
-2007-
(8) Jackson, A. and Finlay, C.C., (2007) Geomagnetic secular variation and applications to the core. Treatise on Geophysics, Volume 5: Geomagnetism, Volume editor M. Kono, Series editor G. Schubert, Elsevier Publishers , Chapter 5.05, 147-193.
(7) Gillet, N. and Jackson, A. and Finlay, C.C., (2007) Maximum entropy regularization of time-dependent geomagnetic field models. Geophys. J. Int., 171, 3, 1005-1016.
(6) Finlay, C.C., (2007) Alfven waves. Ency. Geomag. Paleomag., ed. D. Gubbins and E. Herrero-Bervera., 3-6.
(5) Finlay, C.C., (2007) Magnetohydrodynamic waves. Ency. Geomag. Paleomag., ed. D. Gubbins and E. Herrero-Bervera., 632-639.
(4) Dumberry, M. and Finlay, C.C., (2007) Eastward and westward drift of the Earth's magnetic field in the last three millennia. Earth and Planetary Science Letters, 254, 146-157.
-2006-
(3) Gubbins, D., Jones, A.J. and Finlay, C.C., (2006) Fall in Earth's magnetic field is erratic. Science, 312, 900-902.
-2004-
(2) Hide, R. McSharry, P.E., Finlay, C.C., and Peskett, G.D. (2004) Quenching Lorenzian chaos. Int. J. Bif. and Chaos, 14(8), 2875-2884
-2003-
(1) Finlay, C.C. and Jackson, A., (2003) Equatorially Dominated Magnetic Field Change at the Surface of Earth's Core. Science, 300, 2084-2086.