A dynamo cascade interpretation of the geomagnetic dipole decrease

Geophysical Journal International

Volumn 181, Issue 3, 2010, Pages 1411-1427

  Amit, Hagay ^a   Olson, Peter ^b  

^a UNIVERSITÉ DE NANTES   (France)

^b JOHNS HOPKINS UNIVERSITY   (United States)

Author keywords

Dynamo: theories and simulations; Geomagnetic excursions; Rapid time variations

Indexed keywords

GEODYNAMO; GEOMAGNETIC FIELD; GEOMAGNETISM; MAGNETIC INTENSITY; NUMERICAL MODEL; SECULAR VARIATION; SPHERICAL HARMONICS;

EID: 77954066985     PISSN: 0956540X     EISSN: 1365246X     Source Type: Journal    
DOI: 10.1111/j.1365-246X.2010.04596.x     Document Type: Article

References (59)

1. Alexakis A, Mininni P, Pouquet A. Imprint of large-scale flows on turbulence. Phys. Rev. Lett. 2005, 93:264503.
2. Alexakis A, Mininni P, Pouquet A. Turbulent cascades, transfer, and scale interactions in magnetohydrodynamics. New J. Phys. 2007, 9:1-20.
3. Alldredge L. Harmonics required in main field and secular varaition models. J. Geomagn. Geoelectr. 1984, 36:63-72.
4. Amit H, Christensen U. Accounting for magnetic diffusion in core flow inversions from geomagnetic secular variation. Geophys. J. Int. 2008, 175:913-924.
5. Amit H, Olson P. Time-average and time-dependent parts of core flow. Phys. Earth planet. Inter. 2006, 155:120-139.
6. Amit H, Olson P. Geomagnetic dipole tilt changes induced by core flow. Phys. Earth planet. Inter. 2008, 166:226-238.
7. Backus G, Parker R, Constable C. Foundations of Geomagnetism 1996, Cambridge University Press, Cambridge, UK
8. Benton E, Alldredge L. On the interpretation of the geomagnetic energy spectrum. Phys. Earth planet. Inter. 1987, 48:265-278.
9. Benton E, Voorhies C. Testing recent geomagnetic field models via magnetic flux conservation at the core-mantle boundary. Phys. Earth planet. Inter. 1987, 48:350-357.
10. Biskamp D. Magnetohydrodynamic Turbulence 2003, Cambridge University Press, Cambridge, UK
11. Bloxham J. The expulsion of magnetic flux from the Earth's core. Geophys. J. R. astr. Soc. 1986, 87:669-678.
12. Bloxham J, Jackson A. Fluid flow near the surface of the Earth's outer core. Rev. Geophys. 1991, 29:97-120.
13. Boldyrev S. Spectrum of magnetohydrodynamic turbulence. Phys. Rev. Lett. 2006, 96:115002.
14. Cain J, Wang Z, Schmitz D, Meyer J. The geomagnetic spectrum for 1989 and core-crustal separation. Geophys. J. 1989, 97:443-447.
15. Cho J, Lazarian A, Vishniac E. Simulations of magnetohydrodynamic turbulence in a strongly magnetized medium. Astr. J. 2002, 564:291-301.
16. Christensen U, Tilgner A. Power requirement of the geodynamo from ohmic losses in numerical and laboratory dynamos. Nature 2004, 439:169-171.
17. Corrsin S. The reactant concentration spectrum in turbulent mixing with a first-order reaction. J. Fluid Mech. 1961, 11:407-416.
18. Corrsin S. Further generalization of Onsager's cascade model for turbulent spectra. Phys. Fluids 1964, 7:1156-1159.
19. Dormy E, Valet J-P, Courtillot V. Numerical models of the geodynamo and observational constraints. Geochem. Geophys. Geosyst. 2000, 1(10):1037. 10.1029/2000GC000062, doi
20. Eymin C, Hulot G. On surface core flows inferred from satellite magnetic data. Phys. Earth planet. Inter. 2005, 152:200-220.
21. Finlay C. Historical variation of the geomagnetic axial dipole. Phys. Earth planet. Inter. 2008, 170:1-14.
22. Frisch U. Turbulence: The Legacy of A.N. Kolmogorov 1995, Cambridge University Press, Cambridge, UK
23. Gillet N, Pais M, Jault D. Ensmeble inversion of time-dependent core flow models. Geochem. Geophys. Geosyst. 2009, 10:Q06004.
24. Gubbins D. Mechanism for geomagnetic polarity reversals. Nature 1987, 326:167-169.
25. Gubbins D, Jones A, Finlay C. Fall in Earth's magnetic field is erratic. Science 2006, 312:900-902.
26. Hill R. Models of the scalar spectrum for turbulent advection. J. Fluid Mech. 1978, 88:541-562.
27. Holme R. Large-scale flow in the core. Treatise on Geophysics 2007, Olson P. Vol. 8, ed., Elsevier Science, London
28. Holme R, Olsen N. Core surface flow modelling from high-resolution secular variation. Geophys, J. Int. 2006, 166:518-528.
29. Holme R, Whaler K. Steady core flow in an azimuthally drifting frame. Geophys. J. Int. 2001, 145:560-569.
30. Hongre L, Hulot G, Khokhlov A. An analysis of the geomagnetic field over the past 2000 years. Phys. Earth planet. Inter. 1998, 106:311-335.
31. Hulot G, LeMouël J-L. A statistical approach to the Earth's main magnetic field. Phys. Earth planet. Inter. 1994, 82:167-183.
32. Hulot G, Lhuillier F, Aubert J. Earth's dynamo limit of predictability. Geophys. Res. Lett. 37:L06305. 10.1029/2009GL041869, doi
33. Jackson A. Time-dependency of tangentially geostrophic core surface motions. Phys. Earth Planet. Inter. 1997, 103:293-311.
34. Jackson A, Jonkers A, Walker M. Four centuries of geomagnetic secular variation from historical records. Phil. Trans. R. Soc. Lond. A 2000, 358:957-990.
35. Korte M, Constable C. Continuous geomagnetic field models for the past 7 millennia: 2. CALS7K. Geochem. Geophys. Geosyst. 2005, 6(2). 10.1029/2004GC000801, doi
36. Kutzner C, Christensen U. From stable dipolar towards reversing numerical dynamos. Phys. Earth planet. Inter. 2002, 131:29-45.
37. Liu L, Olson P. Geomagnetic dipole moment collapse by convective mixing in the core. Geophys. Res. Lett. 2009, 36:L10305. 10.1029/2009GL038130, doi
38. Lowes F. Spatial power spectrum of the main geomagnetic field. Geophys. J. R. astr. Soc. 1974, 36:717-730.
39. Maron J, Goldreich P. Simulations of incompressible magnetohydrodynamic turbulence. Astr. J. 2001, 554:1175-1196.
40. McLeod M. Spatial and temporal power spectra of the geomagnetic field. J. geophys. Res. 1996, 101:2745-2764.
41. Moffatt H. Magnetic Field Generation in Electrically Conducting Fluids 1978, Cambridge University Press, Cambridge, UK
42. Müller W, Grappin R. Spectral energy dynamics in magnetohydrodynamic turbulence. Phys. Rev. Lett. 2005, 95:114502.
43. Olsen N, Mandea M. Rapidly changing flows in the Earth's core. Nat. Geosci. 2008, 1:390-394.
44. Olson P. Gravitational dynamos and the low frequency geomagnetic secular variation. Proc. Natl. Acad. Sci. U.S.A. 2007, 104:20 159-20 166.
45. Olson P, Amit H. Changes in earth's dipole. Naturwissenschaften 2006, 93:519-542.
46. Olson P, Driscoll P, Amit H. Dipole collapse and reversal precursors in a numerical dynamo. Phys. Earth planet. Inter. 2009, 173:121-140.
47. Pais MA, Jault D. Quasi-geostrophic flows responsible for the secular variation of the Earth's magnetic field. Geophys. J. Int. 2008, 10.1111/j.1365--246X.2008.03741.x, doi
48. Poirier J-P. Introduction to the Physics of the Earth's Interior 2000, Cambridge University Press, Cambridge, UK
49. Pouquet A, Frisch U, Léeorat J. Strong MHD helical turbulence and the nonlinear dynamo effect. J. Fluid Mech. 1976, 77:321-354.
50. Roberts P. Dynamo theory. Mathematical Problems in the Geophysical Sciences 1971, Reid W. ed., Amer. Math. Soc., Providence, Rhode Island
51. Roberts P, Scott S. On analysis of the secular variation, 1, a hydromagnetic constraint: theory. J. Geomagn. Geoelectr. 1965, 17:137-151.
52. Verosub K, Cox A. Changes in the total magnetic energy external to the Earth's core. J. Geomagn. Geoelectr. 1971, 23:235-242.
53. Voorhies C. Coupling an inviscid core to an electrically insulating mantle. J. Geomagn. Geoelectr. 1991, 43:131-156.
54. Voorhies C. Geomagnetic estimates of steady surficial core flow and flux diffusion: unexpected geodynamo experiments. Dynamics of Earth's deep interior and Earth rotation 1993, LeMouël J-LSmylie DHerring T. Vol. 12, eds, Geophysical Monograph 72 IUGG
55. Voorhies C. Narrow-scale flow and a weak field by the top of Earth's core: evidence from Orsted, Magsat, and secular variation. J. geophys. Res. 2004, 109. 10.1029/2003JB002833, doi
56. Voorhies C, Backus G. Steady flows at the top of the core from geomagnetic field models - the steady motions theorem. Geophys. Astrophys. Fluid Dyn. 1985, 32:163-173.
57. Whaler K, Davis R. Probing the Earth's core with geomagnetism. Earth's Deep Interior 1997, Crossley D, ed., Gordon and Breach, Amsterdam, the Netherlands
58. Wiltse J, Glezer A. Manipulation of free shear flows using piezoelectric actuators. J. Fluid Mech. 1993, 249:261-285.
59. Yousef T, Rincon F, Schekochihin A. Exact scaling laws and the local structure of isotropic magnetohydrosdynamic turbulence. J. Fluid Mech. 2007, 575:111-120.