Skip to main content
SpringerLink
Log in

Short Timescale Core Dynamics: Theory and Observations

  • Published:
Space Science Reviews Aims and scope Submit manuscript

Abstract

Fluid motions in the Earth’s core produce changes in the geomagnetic field (secular variation) and are also an important ingredient in the planet’s rotational dynamics. In this article we review current understanding of core dynamics focusing on short timescales of years to centuries. We describe both theoretical models and what may be inferred from geomagnetic and geodetic observations. The kinematic concepts of frozen flux and magnetic diffusion are discussed along with relevant dynamical regimes of magnetostrophic balance, tangential geostrophy, and quasi-geostrophy. An introduction is given to free modes and waves that are expected to be present in Earth’s core including axisymmetric torsional oscillations and non-axisymmetric Magnetic-Coriolis waves. We focus on important recent developments and promising directions for future investigations.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Log in via an institution

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Institutional subscriptions

Similar content being viewed by others

References

  • R. Abarca del Rio, D. Gambis, D.A. Salatein, Interannual signals in length of day and atmospheric angular momentum. Ann. Geophys. 18, 347–364 (2000)

    ADS  Google Scholar 

  • D.J. Acheson, On hydromagnetic stability of a rotating fluid annulus. J. Fluid Mech. 52(3), 529–541 (1972)

    Article  MATH  MathSciNet  ADS  Google Scholar 

  • D.J. Acheson, R. Hide, Hydromagnetics of rotating fluids. Rep. Prog. Phys. 36, 159–221 (1973)

    Article  ADS  Google Scholar 

  • H. Alfvén, On the existence of electromagnetic-hydromagnetic waves. Nature 150, 405–406 (1942)

    Article  ADS  Google Scholar 

  • D.W. Allan, E.C. Bullard, The secular variation of the Earth’s magnetic field. Proc. Camb. Philos. Soc. 62(3), 783–809 (1966)

    Article  Google Scholar 

  • H. Amit, U.R. Christensen, Accounting for magnetic diffusion in core flow inversions from geomagnetic secular variation. Geophys. J. Int. 175, 913–924 (2008)

    Article  ADS  Google Scholar 

  • H. Amit, P. Olson, Helical core flows from geomagnetic secular variations. Phys. Earth Planet. Inter. 147, 1–25 (2004)

    Article  ADS  Google Scholar 

  • H. Amit, P. Olson, Time-average and time-dependent parts of core flows. Phys. Earth Planet. Inter. 155, 120–139 (2006)

    Article  ADS  Google Scholar 

  • H. Amit, P. Olson, U. Christensen, Tests of core flow imaging methods with numerical dynamos. Geophys. J. Int. 168, 27–39 (2007)

    Article  ADS  Google Scholar 

  • H. Amit, J. Aubert, G. Hulot, P. Olson, A simple model for mantle-driven flow at the top of the Earth’s core. Earth Planets Space 60, 845–854 (2008)

    ADS  Google Scholar 

  • S. Asari, H. Shimizu, H. Utada, Robust and less robust features in the tangential geostrophy core flows. Geophys. J. Int. 178, 678–692 (2009)

    Article  ADS  Google Scholar 

  • J. Aubert, Steady zonal flows in spherical shell fluid dynamos. J. Fluid Mech. 542, 53–67 (2005)

    Article  MATH  ADS  Google Scholar 

  • J. Aubert, N. Gillet, P. Cardin, Quasigeostrophic models of convection in rotating spherical shells. Geochem. Geophys. Geosyst. 4, 1052 (2003). doi:10.1029/2002GC000456

    Article  ADS  Google Scholar 

  • J. Aubert, H. Amit, G. Hulot, Detecting thermal boundary control in surface flows from numerical dynamos. Phys. Earth Planet. Inter. 160, 143–156 (2007)

    Article  ADS  Google Scholar 

  • J. Aubert, J. Aurnou, J. Wicht, The magnetic structure of convection-driven numerical dynamos. Geophys. J. Int. 172, 945–966 (2008)

    Article  ADS  Google Scholar 

  • J. Aubert, J. Tarduno, C. Johnson, Observations and models of the long-term evolution of Earth’s Magnetic Field. Space Sci. Rev. (2010). doi:10.1007/s11214-010-9684-5

    Google Scholar 

  • G. Backus, Kinematics of geomagnetic secular variation in a perfectly conducting core. Philos. Trans. R. Soc. Lond. A 263, 239–266 (1968)

    Article  ADS  Google Scholar 

  • G. Backus, Bayesian inference in geomagnetism. Geophys. J. Int. 92, 125–142 (1988)

    Article  MATH  ADS  Google Scholar 

  • G.E. Backus, J.L. Le Mouël, The region on the core-mantle boundary where a geostrophic velocity field can be determined from frozen-flux magnetic data. Geophys. J. R. Astron. Soc. 85, 617–628 (1986)

    Google Scholar 

  • E.R. Benton, K.A. Whaler, Rapid diffusion of the poloidal geomagnetic field through the weakly conducting mantle: a perturbation solution. Geophys. J. Int. 75, 77–100 (1983)

    Article  MATH  ADS  Google Scholar 

  • J. Bloxham, The expulsion of magnetic flux from the Earth’s outer core. Geophys. J. R. Astron. Soc. 87, 669–678 (1986)

    Google Scholar 

  • J. Bloxham, D. Gubbins, Geomagnetic field analysis—IV. Testing the frozen-flux hypothesis. Geophys. J. R. Astron. Soc. 84, 139–152 (1986)

    ADS  Google Scholar 

  • J. Bloxham, A. Jackson, Lateral temperature variations at the core-mantle boundary deduced from the magnetic field. Geophys. Res. Lett. 17, 1997–2000 (1990)

    Article  ADS  Google Scholar 

  • J. Bloxham, A. Jackson, Fluid flow near the surface of Earth’s outer core. Rev. Geophys. 29, 97–120 (1991)

    Article  ADS  Google Scholar 

  • J. Bloxham, A. Jackson, Time dependent mapping of the geomagnetic field at the core-mantle boundary. J. Geophys. Res. 97, 19537–19564 (1992)

    Article  ADS  Google Scholar 

  • J. Bloxham, D. Gubbins, A. Jackson, Geomagnetic secular variation. Philos. Trans. R. Soc. Lond. A 329(1606), 415–502 (1989)

    Article  ADS  Google Scholar 

  • J. Bloxham, S. Zatman, M. Dumberry, The origin of geomagnetic jerks. Nature 420, 65–68 (2002)

    Article  ADS  Google Scholar 

  • S.I. Braginsky, Magnetohydrodynamics of the Earth’s core. Geomagn. Aeron. 4, 698–712 (1964)

    Google Scholar 

  • S.I. Braginsky, Magnetic waves in the Earth’s core. Geomagn. Aeron. 7, 851–859 (1967)

    Google Scholar 

  • S.I. Braginsky, Torsional magnetohydrodynamic vibrations in the Earth’s core and variations in day length. Geomagn. Aeron. 10, 1–10 (1970)

    ADS  Google Scholar 

  • S.I. Braginsky, Analytic description of the geomagnetic field of past epochs and determination of the spectrum of magnetic waves in the core of the Earth I. Geomagn. Aeron. 12, 947–957 (1972)

    ADS  Google Scholar 

  • S.I. Braginsky, Short-period geomagnetic secular variation. Geophys. Astrophys. Fluid Dyn. 30, 1–78 (1984)

    Article  MATH  ADS  Google Scholar 

  • S.I. Braginsky, P.H. Roberts, Equations governing convection in Earth’s core and the geodynamo. Geophys. Astrophys. Fluid Dyn. 79, 1–97 (1995)

    Article  ADS  Google Scholar 

  • B.A. Buffett, Free oscillations in the length of day: inferences on physical properties near the core-mantle boundary, in The Core-mantle Boundary Region, ed. by M. Gurnis, M.E. Wysession, E. Knittle, B.A. Buffett. Geodynamics Series, vol. 28 (AGU Geophysical Monograph, Washington, 1998), pp. 153–165

    Google Scholar 

  • B.A. Buffett, J. Mound, A. Jackson, Inversion of torsional oscillations for the structure and dynamics of Earth’s core. Geophys. J. Int. 177, 878–890 (2009)

    Article  ADS  Google Scholar 

  • F.H. Busse, The dynamical coupling between inner core and mantle of the Earth and the 24-year libration of the pole, in Earthquake Displacement Fields and the Rotation of the Earth, ed. by D. Mansinha, D.E. Smylie, A.E. Beck. Astrophysics and Space Science Library, vol. 20 (Reidel, Dordrecht, 1970), pp. 88–98

    Google Scholar 

  • F.H. Busse, C. Carrigan, Laboratory simulation of thermal convection in rotating planets and stars. Science 191, 81–83 (1976)

    Article  ADS  Google Scholar 

  • F.H. Busse, R. Simitev, Convection in rotating spherical fluid shells and its dynamo states, in Fluid Dynamics and Dynamos in Astrophysics and Geophysics, ed. by A.M. Soward, C.A. Jones, D.W. Hugues, N.O. Weiss. The Fluid Mechanics of Astrophysics and Geophysics (Taylor & Francis, London, 2005), pp. 359–392

    Google Scholar 

  • E. Canet, Modèle dynamique et assimilation de données de la variation séculaire du champ magnétique terrestre. Ph.D. thesis, Université Joseph Fourier de Grenoble (2009)

  • E. Canet, A. Fournier, D. Jault, Forward and adjoint quasi-geostrophic models of the geomagnetic secular variation. J. Geophys. Res. 114 (2009). doi:10.1029/2008JB006189

  • P. Cardin, P. Olson, An experimental approach to thermochemical convection in the Earth’s core. Geophys. Res. Lett. 19, 1995–1998 (1992)

    Article  ADS  Google Scholar 

  • P. Cardin, P. Olson, Chaotic thermal convection in a rapidly rotating spherical shell: consequences for flow in the outer core. Phys. Earth Planet. Inter. 82, 235–259 (1994)

    Article  ADS  Google Scholar 

  • C. Carrigan, F.H. Busse, An experimental and theoretical investigation of the onset of convection in rotating spherical shells. J. Fluid Mech. 126, 287–305 (1983)

    Article  MATH  ADS  Google Scholar 

  • S. Chandrasekhar, Hydrodynamic and Hydromagnetic Stability (Clarendon, Oxford, 1961), pp. 196–219

    MATH  Google Scholar 

  • U.R. Christensen, J. Aubert, Scaling properties of convection-driven dynamos in rotating spherical shells and application to planetary magnetic fields. Geophys. J. Int. 166, 97–114 (2006)

    Article  ADS  Google Scholar 

  • U.R. Christensen, P. Olson, Secular variation in numerical geodynamo models with lateral variations of boundary heat flow. Geophys. J. Int. 138, 39–54 (2003)

    Google Scholar 

  • U.R. Christensen, J. Wicht, Numerical dynamo simulations, in Treatise on Geophysics, vol. 8, ed. by P. Olson (Elsevier, Amsterdam, 2007), pp. 245–282

    Google Scholar 

  • A. Chulliat, Geomagnetic secular variation generated by a tangentially geostrophic flow under the frozen-flux assumption—II. Sufficient conditions. Geophys. J. Int. 157, 537–552 (2004)

    Article  ADS  Google Scholar 

  • A. Chulliat, G. Hulot, Local computation of the geostrophic pressure at the top of the core. Phys. Earth Planet. Inter. 117, 309–328 (2000)

    Article  ADS  Google Scholar 

  • A. Chulliat, G. Hulot, Geomagnetic secular variation generated by a tangentially geostrophic flow under the frozen-flux assumption—I. Necessary conditions. Geophys. J. Int. 147, 237–246 (2001)

    Article  ADS  Google Scholar 

  • A. Chulliat, N. Olsen, Observation of magnetic diffusion in the Earth’s outer core from Magsat, Oersted and CHAMP data. J. Geophys. Res. 115, B05105 (2010). doi:10.1029/2009JB006994

    Article  Google Scholar 

  • A. Chulliat, G. Hulot, L. Newitt, Magnetic flux expulsion from the core as a possible cause of the unusually large acceleration of the north magnetic pole during the 1990s. J. Geophys. Res. 115, B07101 (2010). doi:10.1029/2009JB007143

    Article  Google Scholar 

  • C.G. Constable, R.L. Parker, P. Stark, Geomagnetic field models incorporating frozen-flux constraints. Geophys. J. Int. 113, 419–433 (1993)

    Article  ADS  Google Scholar 

  • P. Davidson, An Introduction to Magnetohydrodynamics (Cambridge University Press, Cambridge, 2001)

    Book  MATH  Google Scholar 

  • E. Dormy, A.M. Soward, C.A. Jones, D. Jault, Cardin, The onset of thermal convection in rotating spherical shells. J. Fluid Mech. 501, 43–70 (2004)

    Article  MATH  MathSciNet  ADS  Google Scholar 

  • E. Dormy, P.H. Roberts, A.M. Soward, Core, boundary layers, in Encyclopedia of Geomagnetism and Paleomagnetism (Springer, Berlin, 2007)

    Google Scholar 

  • S.J. Drew, Magnetic field expulsion into a conducting mantle. Geophys. J. Int. 115, 303–312 (1993)

    Article  ADS  Google Scholar 

  • M. Dumberry, Gravity variations induced by core flows. Geophys. J. Int. 180, 635–650 (2010)

    Article  ADS  Google Scholar 

  • M. Dumberry, J. Bloxham, Torque balance, Taylor’s constraint and torsional oscillations in a numerical model of the geodynamo. Phys. Earth Planet. Inter. 140, 29–51 (2003)

    Article  ADS  Google Scholar 

  • M. Dumberry, J.E. Mound, Constraints on core-mantle electromagnetic coupling from torsional oscillation normal modes. J. Geophys. Res. 113, B03102 (2008). doi:10.1029/2007JB005135

    Article  Google Scholar 

  • A.M. Dziewonski, D.L. Anderson, Preliminary reference Earth model. Phys. Earth Planet. Inter. 25, 297–356 (1981)

    Article  ADS  Google Scholar 

  • C. Eymin, G. Hulot, On core surface flows inferred from satellite magnetic data. Phys. Earth Planet. Inter. 152, 200–220 (2005)

    Article  ADS  Google Scholar 

  • D.R. Fearn, Differential rotation and thermal convection in a rapidly rotating hydromagnetic system. Geophys. Astrophys. Fluid Dyn. 49, 173–193 (1989)

    Article  MATH  MathSciNet  ADS  Google Scholar 

  • D.R. Fearn, Magnetic instabilities in rapidly rotating systems, in Theory of Solar and Planetary Dynamos, ed. by M.R.E. Proctor, P.C. Matthews, A.M. Rucklidge (1993), pp. 59–68

  • D.R. Fearn, Nonlinear planetary dynamos, in Lectures on Solar and Planetary Dynamos, ed. by M.R.E. Proctor, A.D. Gilbert (Cambridge University Press, Cambridge, 1994)

    Google Scholar 

  • D.R. Fearn, Hydromagnetic flow in planetary cores. Rep. Prog. Phys. 61, 175–235 (1998)

    Article  ADS  Google Scholar 

  • C.C. Finlay, Waves in the presence of magnetic fields, rotation and convection. Les Houches Summer School Proc. 88, 403–450 (2008)

    Article  Google Scholar 

  • C.C. Finlay, A. Jackson, Equatorially dominated magnetic field change at the surface of Earth’s core. Science 300, 2084–2086 (2003)

    Article  ADS  Google Scholar 

  • A. Fournier, G. Hulot, D. Jault, W. Kuang, A. Tangborn, N. Gillet, E. Canet, J. Aubert, F. Lhuillier, An introduction to data assimilation and predictability in geomagnetism. Space Sci. Rev. (2010, accepted). doi:10.1007/s11214-010-9669-4

  • E. Friis-Christensen, H. Lühr, G. Hulot, Swarm: A constellation to study the Earth’s magnetic field. Earth Planets Space 58, 351–358 (2006)

    ADS  Google Scholar 

  • H. Gellibrand, A Discourse Mathematical on the Variation of the Magnetic Needle. Together with Its Admirable Diminution Lately Discovered (William Jones, London, 1635)

    Google Scholar 

  • A.D. Gilbert, Dynamo Theory, ed. by S. Friedlander, D. Serre. Handbook of Mathematical Fluid Dynamics, vol. 2 (Elsevier, New York, 2003), pp. 355–441

    Google Scholar 

  • A.E. Gill, Atmosphere-Ocean Dynamics (Academic Press, San Diego, 1982)

    Google Scholar 

  • N. Gillet, C.A. Jones, The quasi-geostrophic model for rapidly rotating spherical convection outside the tangent cylinder. J. Fluid Mech. 554, 343–369 (2006)

    Article  MATH  MathSciNet  ADS  Google Scholar 

  • N. Gillet, V. Lesur, N. Olsen, Geomagnetic core field secular variation models. Space Sci. Rev. (2009a). doi:10.1007/s11214-009-9586-6

    Google Scholar 

  • N. Gillet, A. Pais, D. Jault, Ensemble inversion of time-dependent core flow models. Geochem. Geophys. Geosyst. 10, Q06004 (2009b). doi:10.1029/2008GC002290

    Article  Google Scholar 

  • N. Gillet, D. Jault, E. Canet, A. Fournier, Fast torsional waves and strong magnetic field within the Earth’s core. Nature 465, 764–777 (2010)

    Article  Google Scholar 

  • G.A. Glatzmaier, P.H. Roberts, A three-dimensional convective dynamo solution with rotating and finitely conducting inner core and mantle. Phys. Earth Planet. Inter. 91, 63–75 (1995)

    Article  Google Scholar 

  • H.P. Greenspan, The Theory of Rotating Fluids (Cambridge University Press, Cambridge, 1968)

    MATH  Google Scholar 

  • D. Gubbins, Finding core motions from magnetic observations. Philos. Trans. R. Soc. Lond. A 306, 247–254 (1982)

    Article  ADS  Google Scholar 

  • D. Gubbins, Mechanism for geomagnetic polarity reversals. Nature 326, 167–169 (1987)

    Article  ADS  Google Scholar 

  • D. Gubbins, Dynamics of the secular variation. Phys. Earth Planet. Int. 68, 170–182 (1991)

    Article  ADS  Google Scholar 

  • D. Gubbins, A formalism for the inversion of geomagnetic data for core motions with diffusion. Phys. Earth Planet. Inter. 98, 193–206 (1996)

    Article  ADS  Google Scholar 

  • D. Gubbins, Geomagnetic constraints on stratification at the top of the Earth’s core. Earth Planets Space 59, 661–664 (2007)

    ADS  Google Scholar 

  • D. Gubbins, P. Kelly, A difficulty with using the frozen flux hypothesis to find steady core motions. Geophys. Res. Lett. 23, 1825–1828 (1996)

    Article  ADS  Google Scholar 

  • D. Gubbins, P.H. Roberts, Magnetohydrodynamics of the Earth’s core. Geomagnetism 2, 1–183 (1987)

    Google Scholar 

  • E. Halley, A theory of the variation of the magnetical compass. Philos. Trans. R. Soc. Lond. A 13, 208–221 (1683)

    Article  Google Scholar 

  • E. Halley, An account of the cause of the change of the variation of the magnetic needle; with an hypothesis of the structure of the internal part of the Earth. Philos. Trans. R. Soc. Lond. A 17, 563–578 (1692)

    Google Scholar 

  • R. Hide, Free hydromagnetic oscillations of the Earth’s core and the theory of geomagnetic secular variation. Philos. Trans. R. Soc. Lond. A 259, 615–647 (1966)

    Article  ADS  Google Scholar 

  • R. Hide, A note on short-term core-mantle coupling, geomagnetic secular variation impulses, and potential magnetic field invariants as Lagrangian tracers of core motions. Phys. Earth Planet. Int. 39, 297–300 (1985)

    Article  ADS  Google Scholar 

  • R. Hide, K. Stewartson, Hydromagnetic oscillations of the Earth’s core. Rev. Geophys. Space Phys. 10, 579–598 (1972)

    Article  ADS  Google Scholar 

  • R. Hide, D.H. Boggs, J.O. Dickey, Angular momentum fluctuations within the Earth’s liquid core and torsional oscillations of the core-mantle system. Geophys. J. Int. 143, 777–786 (2000)

    Article  ADS  Google Scholar 

  • R.G. Hills, Convection in the Earth’s mantle due to viscous shear at the core-mantle interface and due to large-scale buoyancy. Ph.D. thesis, New Mexico State University (1979)

  • R. Hollerbach, On the theory of the geodynamo. Phys. Earth Planet. Inter. 98, 163–185 (1996)

    Article  ADS  Google Scholar 

  • R. Holme, Large-scale flow in the core, in Treatise on Geophysics, vol. 8, ed. by P. Olson (Elsevier, Amsterdam, 2007)

    Google Scholar 

  • R. Holme, N. Olsen, Core surface flow modelling from high-resolution secular variation. Geophys. J. Int. 166, 518–528 (2006)

    Article  ADS  Google Scholar 

  • S.S. Hough, On the application of harmonic analysis to the dynamic theory of the Tides, part I. On Laplace’s “oscillations of the first species” and on the dynamics of ocean currents. Philos. Trans. R. Soc. Lond. A 189, 201–257 (1897)

    Article  ADS  Google Scholar 

  • G. Hulot, A. Chulliat, On the possibility of quantifying diffusion and horizontal Lorentz forces at the Earth’s core surface. Phys. Earth Planet. Inter. 135, 47–54 (2003)

    Article  ADS  Google Scholar 

  • G. Hulot, C. Eymin, B. Langlais, M. Mandea, N. Olsen, Small-scale structure of the geodynamo inferred from Oersted and Magsat satellite data. Nature 416, 620–623 (2002)

    Article  ADS  Google Scholar 

  • A. Jackson, Kelvin’s theorem applied to the Earth’s core. Proc. R. Soc. London, Ser. A 452, 2195–2201 (1996)

    Article  MATH  ADS  Google Scholar 

  • A. Jackson, Time-dependency of tangentially geostrophic core surface motions. Phys. Earth Planet. Inter. 103, 293–311 (1997)

    Article  ADS  Google Scholar 

  • A. Jackson, Intense equatorial flux spots on the surface of Earth’s core. Nature 424, 760–763 (2003)

    Article  ADS  Google Scholar 

  • A. Jackson, C.C. Finlay, Geomagnetic secular variation and its applications to the core, in Treatise on Geophysics, vol. 5, ed. by G. Schubert (Elsevier, Amsterdam, 2007), pp. 147–193

    Chapter  Google Scholar 

  • A. Jackson, J. Bloxham, D. Gubbins, Time-dependent flow at the core surface and conservation of angular momentum in the coupled core-mantle system, in Dynamics of the Earth’s Deep Interior and Earth Rotation, vol. 72, ed. by J.L. Le Mouël, D.E. Smylie, T. Herring (AGU Geophysical Monograph, Washington, 1993), pp. 97–107

    Google Scholar 

  • A. Jackson, A.R.T. Jonkers, M.R. Walker, Four centuries of geomagnetic secular variation from historical records. Philos. Trans. R. Soc. Lond. A 358, 957–990 (2000)

    Article  ADS  Google Scholar 

  • A. Jackson, C.G. Constable, M.R. Walker, R.L. Parker, Models of Earth’s main magnetic field incorporating flux and radial vorticity constraints. Geophys. J. Int. 171, 133–144 (2007)

    Article  ADS  Google Scholar 

  • D. Jault, Electromagnetic and topographic coupling, and lod variations, in Earth’s Core and Lower Mantle, ed. by C.A. Jones, A. Soward, K. Zhang. The Fluid Mechanics of Astrophysics And Geophysics (Taylor & Francis, London, 2003), pp. 56–76

    Google Scholar 

  • D. Jault, Axial invariance of rapidly varying diffusionless motions in the Earth’s core interior. Phys. Earth Planet. Inter. 166, 67–76 (2008)

    ADS  Google Scholar 

  • D. Jault, J.L. Le Mouël, Physical properties at the top of the core and core surface motions. Phys. Earth Planet. Inter. 68, 76–84 (1991)

    Article  ADS  Google Scholar 

  • D. Jault, G. Légaut, Alfvén waves within the Earth’s core, in Fluid Dynamics and Dynamos in Astrophysics and Geophysics, ed. by A.M. Soward, C.A. Jones, D.W. Hugues, N.O. Weiss. The Fluid Mechanics of Astrophysics and Geophysics (Taylor & Francis, London, 2005), pp. 277–293

    Google Scholar 

  • D. Jault, C. Gire, J.L. Le Mouël, Westward drift, core motions and exchanges of angular momentum between core and mantle. Nature 333, 353–356 (1988)

    Article  ADS  Google Scholar 

  • D. Jault, G. Hulot, J.L. Le Mouël, Mechanical core-mantle coupling and dynamo modelling. Phys. Earth Planet. Inter. 98, 187–191 (1996)

    Article  ADS  Google Scholar 

  • C.A. Jones, Dynamos in planets, in Stellar Astrophysical Fluid Dynamics, ed. by M. Thompson, J. Christensen-Dalsgaard (Cambridge University Press, Cambridge, 2003), pp. 159–178

    Chapter  Google Scholar 

  • C.A. Jones, Thermal and compositional convection in the outer core, in Treatise in Geophysics, Core Dynamics, vol. 8, ed. by P. Olson (Amsterdam, 2007), pp. 131–185

  • C.A. Jones, A.N. Soward, A.I. Mussa, The onset of convection in a rapidly rotating sphere. J. Fluid Mech. 405, 157–179 (2000)

    Article  MATH  MathSciNet  ADS  Google Scholar 

  • C.A. Jones, A.I. Mussa, S.J. Worland, Magnetoconvection in a rapidly rotating sphere: the weak-field case. Proc. R. Soc. Lond. A 459, 773–797 (2003)

    Article  MATH  MathSciNet  ADS  Google Scholar 

  • A. Kageyama, T. Miyagoshi, T. Satu, Formation of current coils in geodynamo simulations. Nature 454, 1106–1109 (2008)

    Article  ADS  Google Scholar 

  • R.R. Kerswell, Tidal excitation of hydromagnetic waves and their damping in the Earth. J. Fluid Mech. 274, 219–241 (1994)

    Article  MATH  MathSciNet  ADS  Google Scholar 

  • M.D. Kohler, D.J. Stevenson, Modeling core fluid motions and the drift of magnetic field patterns at the CMB by use of topography obtained by seismic inversion. Geophys. Res. Lett. 17, 1473–1476 (1990)

    Article  ADS  Google Scholar 

  • J.L. Le Mouël, Outer core geostrophic flow and secular variation of Earth’s geomagnetic field. Nature 311, 734–735 (1984)

    Article  ADS  Google Scholar 

  • J.L. Le Mouël, C. Gire, T. Madden, Motions at core surface in the geostrophic approximation. Phys. Earth Planet. Inter. 39, 270–287 (1985)

    Article  ADS  Google Scholar 

  • B. Lehnert, Magnetohydrodynamic waves under the action of the Coriolis force. Astrophys. J. 119, 647–654 (1954)

    Article  MathSciNet  ADS  Google Scholar 

  • V. Lesur, I. Wardinski, M. Rother, M. Mandea, GRIMM: the GFZ reference internal magnetic model based on vector satellite and observatory data. Geophys. J. Int. 173, 382–394 (2008)

    Article  ADS  Google Scholar 

  • V. Lesur, I. Wardinski, S. Asari, B. Minchev, M. Mandea, Modelling the Earth’s core magnetic field under flow constraints. Earth Planets Space 62, 503–516 (2010)

    Article  ADS  Google Scholar 

  • P.W. Livermore, G. Ierley, A. Jackson, The structure of Taylor’s constraint in three dimensions. Proc. R. Soc. Lond. A 464, 3149–3174 (2008)

    Article  MATH  MathSciNet  ADS  Google Scholar 

  • P.W. Livermore, G. Ierley, A. Jackson, The construction of exact Taylor states. I: The full sphere. Geophys. J. Int. 179, 923–928 (2009)

    Article  ADS  Google Scholar 

  • J.J. Love, A critique of frozen-flux inverse modelling of a nearly steady geodynamo. Geophys. J. Int. 138, 353–365 (1999)

    Article  ADS  Google Scholar 

  • W.V.R. Malkus, Hydromagnetic planetary waves. J. Fluid Mech. 28(4), 793–802 (1967)

    Article  MATH  MathSciNet  ADS  Google Scholar 

  • M. Mandea, R. Holme, A. Pais, A. Jackson, E. Qamili, Geomagnetic jerks: rapid core field variations and core dynamics (2010). doi:10.1007/s11214-010-9663-x

  • J. Matzka, A. Chulliat, M. Mandea, C. Finlay, E. Qamili, Direct observations from main field studies: from ground to space (2010). doi:10.1007/s11214-010-9693-4

  • S. Maus, On the applicability of the frozen flux approximation in core flow modelling as a function of temporal frequency and spatial degree. Geophys. J. Int. 175, 853–856 (2008)

    Article  ADS  Google Scholar 

  • T. Miyagoshi, A. Kageyama, T. Sato, Zonal flow formation in the Earth’s core. Nature 463, 793–796 (2010)

    Article  ADS  Google Scholar 

  • H.K. Moffatt, Magnetic Field Generation in Electrically Conducting Fluids (Cambridge University Press, Cambridge, 1978)

    Google Scholar 

  • V. Morin, E. Dormy, Time dependent β-convection in rapidly rotating spherical shell. Phys. Fluids 16, 1603–1609 (2004)

    Article  MathSciNet  ADS  Google Scholar 

  • J.E. Mound, B.A. Buffett, Interannual oscillations in the length of day: implications for the structure of mantle and core. J. Geophys. Res. 108(B7), 2334 (2003). doi:10.1029/2002JB002054

    Article  ADS  Google Scholar 

  • J.E. Mound, B.A. Buffett, Mechanisms of core-mantle angular momentum exchange and the observed spectral properties of torsional oscillations. J. Geophys. Res. 110, 08103 (2005). doi:10.1029/2004JB003555

    Article  Google Scholar 

  • J.E. Mound, B.A. Buffett, Detection of a gravitational oscillation in length-of-day. Earth Planet. Sci. Lett. 243, 383–389 (2006)

    Article  ADS  Google Scholar 

  • H.C. Nataf, N. Gagnière, On the peculiar nature of turbulence in planetary dynamos. C. R. Phys. 9, 702–710 (2008)

    ADS  Google Scholar 

  • M. Nornberg, H. Ji, E. Schartman, A. Roach, J. Goodman, Observation of magnetocoriolis waves in a liquid metal Taylor-Couette Experiment. Phys. Rev. Lett. 104, 074501 (2010)

    Article  ADS  Google Scholar 

  • M.S. O’Brien, C.G. Constable, R.L. Parker, Frozen-flux modelling for epochs 1915 and 1980. Geophys. J. Int. 128, 434–450 (1997)

    Article  ADS  Google Scholar 

  • N. Olsen, M. Mandea, Rapidly changing flows in the Earth’s core. Nature Geosci. 1, 390–394 (2008)

    Article  ADS  Google Scholar 

  • N. Olsen, H. Lühr, T. Sabaka, M. Mandea, M. Rother, L. Tøffner-Clausen, S. Choi, CHAOS—A model of Earth’s magnetic field derived from CHAMP ørsted and SAC-C magnetic satellite data. Geophys. J. Int. 166, 67–75 (2006)

    Article  ADS  Google Scholar 

  • N. Olsen, M. Mandea, T.J. Sabaka, L. Tøffner-Clausen, CHAOS-2—A geomagnetic field model derived from one decade of continuous satellite data. Geophys. J. Int. 142 (2009)

  • P. Olson, J. Aurnou, A polar vortex in the Earth’s core. Nature 402, 170–173 (1999)

    Article  ADS  Google Scholar 

  • P. Olson, U.R. Christensen, The time-averaged magnetic field in numerical dynamos with non-uniform boundary heat flow. Geophys. J. Int. 151, 809–823 (2002)

    Article  ADS  Google Scholar 

  • P. Olson, U.R. Christensen, G.A. Glatzmaier, Numerical modeling of the geodynamo: mechanisms of field generation and equilibration. J. Geophys. Res. 104, 10383–10404 (1999)

    Article  ADS  Google Scholar 

  • A. Pais, G. Hulot, Length of day decade variations, torsional oscillations and inner core superrotation: evidence from recovered core surface zonal flows. Phys. Earth Planet. Inter. 118, 291–316 (2000)

    Article  ADS  Google Scholar 

  • M.A. Pais, D. Jault, Quasi-geostrophic flows responsible for the secular variation of the Earth’s magnetic field. Geophys. J. Int. 173, 421–443 (2008)

    Article  ADS  Google Scholar 

  • M.A. Pais, O. Oliveira, F. Nogueira, Nonuniqueness of inverted core-mantle boundary flows and deviations from tangential geostrophy. J. Geophys. Res. 109, B08105 (2004). doi:10.1029/2004JB003012

    Article  Google Scholar 

  • J. Pedlosky, Geophysical Fluid Dynamics (Springer, New-York, 1987)

    MATH  Google Scholar 

  • M.R.E. Proctor, Convection and magnetoconvection in a rapidly rotating sphere, in Lectures on Solar and Planetary Dynamos, ed. by M.R.E. Proctor, A.D. Gilbert (1994), pp. 97–115

  • J. Proudman, On the motions of solids in a liquid possessing vorticity. Proc. R. Soc. Lond. A 92, 408–424 (1916)

    Article  ADS  Google Scholar 

  • S. Rau, U.R. Christensen, A. Jackson, J. Wicht, Core flow inversion tested with numerical dynamo models. Geophys. J. Int. 141, 485–497 (2000)

    Article  ADS  Google Scholar 

  • P.H. Roberts, On the thermal instability of a self-gravitating fluid sphere containing heat sources. Philos. Trans. R. Soc. Lond. A 263, 93–117 (1968)

    Article  MATH  ADS  Google Scholar 

  • P.H. Roberts, G.A. Glatzmaier, A test of the frozen-flux approximation using a new geodynamo model. Philos. Trans. R. Soc. Lond. A 358, 1109–1121 (2000)

    Article  MATH  ADS  Google Scholar 

  • P.H. Roberts, S. Scott, On analysis of the secular variation. J. Geomagn. Geoelectr. 17, 137–151 (1965)

    Google Scholar 

  • P.H. Roberts, K. Stewartson, On finite amplitude convection in a rotating magnetic system. Philos. Trans. R. Soc. Lond. 277, 287–315 (1974)

    Article  ADS  Google Scholar 

  • T.J. Sabaka, N. Olsen, M.E. Purucker, Extending comprehensive models of the Earth’s magnetic field with Ørsted and CHAMP data. Geophys. J. Int. 159, 521–547 (2004)

    Article  ADS  Google Scholar 

  • A. Sakuraba, P. Roberts, Generation of a strong magnetic field using uniform heat flux at the surface of the core. Nature Geosci. 2, 802–805 (2009)

    Article  ADS  Google Scholar 

  • N. Schaeffer, P. Cardin, Quasi-geostrophic model of the instabilities of the Stewartson layer in flat and depth varying containers. Phys. Fluids 17, 104111 (2005)

    Article  MathSciNet  ADS  Google Scholar 

  • N. Schaeffer, P. Cardin, Quasi-geostrophic kinematic dynamos at low magnetic Prandtl number. Earth Planet. Sci. Lett. 245, 595–604 (2006)

    Article  ADS  Google Scholar 

  • D. Schmitt, Magneto-inertial waves in a rotating sphere. Geophys. Astrophys. Fluid Dyn. 104, 135–151 (2010)

    Article  Google Scholar 

  • D. Schmitt, T. Alboussière, D. Brito, P. Cardin, N. Gagnière, D. Jault, H.C. Nataf, Rotating spherical Couette flow in a dipolar magnetic field: experimental study of magneto-inertial waves. J. Fluid Mech. 604, 175–197 (2008)

    Article  MATH  ADS  Google Scholar 

  • B. Sreenivasan, C.A. Jones, Structure and dynamics of the polar vortex in the Earth’s core. Geophys. Res. Lett. 32, L20301 (2005). doi:10.1029/2005GL023841

    Article  ADS  Google Scholar 

  • B. Sreenivasan, C.A. Jones, Azimuthal winds, convection and dynamo action in the polar regions of planetary cores. Geophys. Astrophys. Fluid Dyn. 100, 319–339 (2006)

    Article  MathSciNet  ADS  Google Scholar 

  • F.D. Stacey, Core properties, physical, in Encyclopedia of Geomagnetism and Paleomagnetism, ed. by D. Gubbins, E. Herrero-Bervera (Springer, Dordrecht, 2007), pp. 91–94

    Chapter  Google Scholar 

  • F. Takahashi, M. Matsushima, Dynamo action in a rotating spherical shell at high Rayleigh numbers. Phys. Fluids 17, 076601 (2005)

    Article  MathSciNet  ADS  Google Scholar 

  • F. Takahashi, M. Matsushima, Y. Honkura, Simulations of a quasi-Taylor state geomagnetic field including polarity reversals on the Earth simulator. Science 309, 459–461 (2005)

    Article  ADS  Google Scholar 

  • F. Takahashi, M. Matsushima, Y. Honkura, Scale variability in convection-driven mhd dynamos at low Ekman number. Phys. Earth Planet. Inter. 167, 168–178 (2008a)

    Article  ADS  Google Scholar 

  • F. Takahashi, H. Tsunakawa, M. Matsushima, N. Mochizuki, Y. Honkura, Effects of thermally heterogeneous structure in the lowermost mantle on geomagnetic field strength. Earth Planet. Sci. Lett. 272, 738–746 (2008b)

    Article  ADS  Google Scholar 

  • B.D. Tapley, M. Bettadpur, M. Watkins, C. Reigber, The gravity recovery and climate experiment: Mission overview and early results. Geophys. Res. Lett. 31, L09607 (2004). doi:10.1029/2004GL019920

    Article  Google Scholar 

  • G.I. Taylor, Motions of solids in fluid when the flow is not irrotational. Proc. R. Soc. Lond. A 93, 99–113 (1917)

    Article  ADS  Google Scholar 

  • G.I. Taylor, Experiments with rotating fluids. Proc. R. Soc. Lond. A 100, 114–124 (1921)

    Article  ADS  Google Scholar 

  • G.I. Taylor, Experiments on the motion of solid bodies in rotating fluids. Proc. R. Soc. Lond. A 104, 213–218 (1923)

    Article  ADS  Google Scholar 

  • J.B. Taylor, The magneto-hydrodynamics of a rotating fluid and the Earth’s dynamo problem. Proc. R. Soc. Lond. A 274, 274–283 (1963)

    Article  MATH  ADS  Google Scholar 

  • A. Tilgner, F.H. Busse, Finite amplitude convection in rotating spherical fluid shells. J. Fluid Mech. 332, 359–376 (1997)

    MATH  ADS  Google Scholar 

  • I. Wardinski, R. Holme, A time-dependent model of the Earth’s magnetic field and its secular variation for the period 1980–2000. J. Geophys. Res. 111, B12101 (2006). doi:10.1029/2006JB004401

    Article  ADS  Google Scholar 

  • I. Wardinski, R. Holme, S. Asari, M. Mandea, The 2003 geomagnetic jerk and its relation to the core surface flows. Earth Planet. Sci. Lett. 267, 468–481 (2008)

    Article  ADS  Google Scholar 

  • K.A. Whaler, Does the whole of the Earth’s core convect. Nature 287, 528–530 (1980)

    Article  ADS  Google Scholar 

  • J. Wicht, U.R. Christensen, Torsional oscillations in dynamo simulations. Geophys. J. Int. 181, 1367–1380 (2010)

    ADS  Google Scholar 

  • A. Willis, B. Sreenivasan, D. Gubbins, Thermal core-mantle interaction: Exploring regimes for ‘locked’ dynamo action. Phys. Earth Planet. Inter. 165(1–2), 83–92 (2007). doi:10.1016/j.pepi.2007.08.002

    Article  ADS  Google Scholar 

  • S. Zatman, J. Bloxham, Torsional oscillations and the magnetic field within the Earth’s core. Nature 388, 760–763 (1997)

    Article  ADS  Google Scholar 

  • K. Zhang, G. Schubert, Magnetohydrodynamics in rapidly rotating spherical systems. Ann. Rev. Fluid Mech. 32, 409–443 (2000)

    Article  MathSciNet  ADS  Google Scholar 

  • K. Zhang, P. Earnshaw, X. Liao, F. Busse, On inertial waves in a rotating fluid sphere. J. Fluid Mech. 437, 103–119 (2001)

    Article  MATH  MathSciNet  ADS  Google Scholar 

  • K. Zhang, X. Liao, G. Schubert, Nonaxisymmetric instabilities of a toroidal magnetic field in a rotating sphere. J. Fluid Mech. 585, 1124–1137 (2004)

    Google Scholar 

Download references

Author information

Authors and Affiliations

  1. Institut für Geophysik, ETH Zürich, 5 Sonneggstrasse, Zürich, 8092, Switzerland

    C. C. Finlay

  2. Department of Physics, University of Alberta, Edmonton, AB, T6G 2G7, Canada

    M. Dumberry

  3. Equipe de Géomagnétisme, Institut de Physique du Globe de Paris, 4, Place Jussieu, 75252, Paris Cedex 05, France

    A. Chulliat

  4. Physics Department, University of Coimbra, 3004-516, Coimbra, Portugal

    M. A. Pais

Authors
  1. C. C. Finlay
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. M. Dumberry
    View author publications

    You can also search for this author in PubMed Google Scholar

  3. A. Chulliat
    View author publications

    You can also search for this author in PubMed Google Scholar

  4. M. A. Pais
    View author publications

    You can also search for this author in PubMed Google Scholar

Corresponding author

Correspondence to C. C. Finlay.

Rights and permissions

Reprints and permissions

About this article

Cite this article

Finlay, C.C., Dumberry, M., Chulliat, A. et al. Short Timescale Core Dynamics: Theory and Observations. Space Sci Rev 155, 177–218 (2010). https://doi.org/10.1007/s11214-010-9691-6

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s11214-010-9691-6

Keywords

Search

Navigation