Earth's rotational variations due to rapid surface flows at both boundaries of the outer core

Geophysical Journal International

Volumn 184, Issue 1, 2011, Pages 235-246

  Nakada, Masao ^a  

^a KYUSHU UNIVERSITY   (Japan)

Author keywords

Earth rotation variations; Electrical properties; Rapid time variations

Indexed keywords

CONDUCTING LAYERS; CORE SURFACE FLOWS; EARTH ROTATION; ELECTRICAL PROPERTY; ELECTROMAGNETIC (EM) COUPLING; EM COUPLING; GEOMAGNETIC JERKS; GRAVITATIONAL TORQUE; INNER CORE; POLAR MOTION; RADIAL MAGNETIC FIELD; RATE OF CHANGE; RIGID ROTATION; ROOT-MEAN-SQUARE VALUES; SUDDEN CHANGE; SURFACE FLOW; TIME VARIATIONS; TOROIDAL CORES;

GEOMAGNETISM; MAGNETIC FIELDS; ROTATION;

ELECTRIC PROPERTIES;

CHANDLER WOBBLE; CORE-MANTLE BOUNDARY; CRUSTAL STRUCTURE; EARTH ROTATION; ELECTRICAL CONDUCTIVITY; GEODYNAMICS; INNER CORE; LITHOSPHERIC STRUCTURE; MANTLE CONVECTION; NUMERICAL MODEL; OUTER CORE; PLANETARY EVOLUTION; SURFACE FLUX; TEMPORAL VARIATION;

EID: 78650084501     PISSN: 0956540X     EISSN: 1365246X     Source Type: Journal    
DOI: 10.1111/j.1365-246X.2010.04862.x     Document Type: Article

References (53)

1. Amit, H. & Olson, P., 2008. Geomagnetic dipole tilt changes induced by core flow, Phys. Earth planet. Inter., 166, 226-238.
2. Bellanger, E., Le Mouël, J.L., Mandea, M. & Labrosse, S., 2001. Chandler wobble and geomagnetic jerks, Phys. Earth planet. Inter., 124, 95-103.
3. Bloxham, J., 2002. Time-independent and time-dependent behavior of high-latitude flux bundles at the core-mantle boundary, Geophys. Res. Lett., 29(0), 1854, doi:.
4. Bloxham, J., Dumberry, M. & Zatman, S., 2002. The origin of geomagnetic jerks, Nature, 420, 65-68.
5. Braginsky, S.I., 1970. Torsional magnetohydrodynamic vibrations in the Earth's core and variations in day length, Geomagn. Aeron., 10, 1-8 (English translation).
6. Buffett, B.A., 1992. Constraints on magnetic energy and mantle conductivity from the forced nutations of the Earth, J. geophys. Res., 97, 19581-19597.
7. Buffett, B.A., 1997. Geodynamic estimates of the viscosity of the Earth's inner core, Nature, 388, 571-573.
8. Buffett, B.A., Mathews, P.M. & Herring, T.A., 2002. Modeling of nutation and precession: effects of electromagnetic coupling, J. Geophys. Res., 107(B4), 2000, doi:.
9. Buffett, B.A., Mound, J. & Jackson, A., 2009. Inversion of torsional oscillations for the structure and dynamics of Earth's core, Geophys. J. Int., 177, 878-890.
10. Courtillot, V., Ducruix, J. & Le Mouël, J.L., 1978. Sur une accélération récente de la variation séculaire du champ megnétique terrestre, C.R. Acad. Sci. Paris Ser. D, 287, 1095-1098.
11. Dubrovinsky, L. et al ., 2003. Iron-silica interaction at extreme conditions and electrically conducting layer at the base of Earth's mantle, Science, 422, 58-61.
12. Dumberry, M., 2009. Influence of elastic deformations on the inner core wobble, Geophys. J. Int., 178, 57-64.
13. Dumberry, M. & Bloxham, J., 2002. Inner core tilt and polar motion, Geophys. J. Int., 151, 377-392.
14. Dziewonski, A.M. & Anderson, D.L., 1981. Preliminary reference Earth model (PREM), Phys. Earth planet. Inter., 25, 297-356.
15. Gilbert, D., Holschneider, M. & Le Mouël, J.L., 1998. Wavelet analysis of the Chandler wobble, J. geophys. Res., 103, 27069-27089.
16. Gilbert, D. & Le Mouël, J.L., 2008. Inversion of polar motion data: Chandler wobble, phase jumps, and geomagnetic jerks, J. geophys. Res., 113, B10405, doi:.
17. Gubbins, D. & Roberts, P.H., 1987. Magnetohydrodynamics of the Earth's Core, in Geomagnetism, Vol. 2, pp. 1-183, ed. Jacobs, J.A., Academic Press, London
18. Hager, B.H., Clayton, R.W., Richards, M.A., Comer, R.P. & Dziewonski, A.M., 1985. Lower mantle heterogeneity, dynamic topography and the geoid, Nature, 313, 541-545.
19. Holme, R., 1998a. Electromagnetic core-mantle coupling-I. Explaining decadal changes in the length of day, Geophys. J. Int., 132, 167-180.
20. Holme, R., 1998b. Electromagnetic core-mantle coupling II: probing deep mantle conductance, in The Core-Mantle Boundary Region, Geodyn. Ser., Vol. 28, pp. 139-151, eds Gurnis, M., Wysession, M.E., Knittle, E. & Buffett, B.A., AGU, Washington DC, USA
21. Holme, R. & de Viron, O., 2005. Geomagnetic jerks and a high-resolution length-of-day profile for core studies, Geophys. J. Int., 160, 435-440.
22. Holme, R. & Olsen, N., 2006. Core surface flow modelling from high-resolution secular variation, Geophys. J. Int., 166, 518-528.
23. Hulot, G., Eymin, C., Langlais, B., Mandea, M. & Olsen, N., 2002. Small-scale structure of the geodynamo inferred from Oersted and MAGSAT satellite data, Nature, 416, 620-623.
24. IAGA, Division V, Working Group 8, 2003. The 9th Generation International Geomagnetic Reference Field, Phys. Earth planet. Inter., 140, 253-254.
25. Jackson, A., Bloxham, T. & Gubbins, D., 1993. 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, Geophys. Mon. Ser., Vol. 72, pp. 97-107, eds Le Mouël J.-L., Smylie, D.E. & Herring, T., AGU, Washington DC, USA
26. Jackson, A., Jonkers, A.R.T. & Walker, M.R., 2000. Four centuries of geomagnetic secular variation from historical records, Phil. Trans. R. Soc. Lond., 358, 957-990.
27. Jault, D., Gire, C. & Le Mouël, J.L., 1988. Westward drift, core motions and exchanges of angular momentum between core and mantle, Nature, 333, 353-356.
28. Jeanloz, R., 1990. The nature of Earth's core, Ann. Rev. Earth planet. Sci., 18, 357-386.
29. Lambeck, K., 1980. The Earth's Variable Rotation: Geophysical Causes and Consequences, Cambridge University Press, Cambridge
30. Lambeck, K., 1988. Geophysical Geodesy, Oxford University Press, Oxford
31. Le Mouël, J.L., Gire, C. & Madden, T., 1985. Motions at the core surface in geostrophic approximation, Phys. Earth planet. Inter., 39, 270-287.
32. Lerch, F.J., Klosko, S.M., Laubscher, R.E. & Wagner, C.A., 1979. Gravity model improvement using Geos 3 (GEM-9 and 10), J. geophys. Res., 84, 3897-3916.
33. Mandea, M., 2009, Geomagnetic and archeomagnetic jerks: where do we stand?, EOS, Trans. Am. geophys. Un., 90, 208.
34. Markowitz, W., 1960. Latitude and longitude and secular motion of the pole, in Methods and Techniques in Geophysics, pp. 325-361, ed. Runcorn, S.K., Interscience Publishers, London
35. Markowitz, W., 1968. Concurrent astronomical observations for studying continental drift, polar motion, and rotation of the Earth, in Continental Drift, Secular Motion of the Pole and Rotation of the Earth, pp. 25-32, eds. Markowitz, W. & Guinot, B, Springer-Verlag, Dordrecht
36. Mathews, P.M., Buffett, B.A., Herring, T.A. & Shapiro, I.I., 1991a. Forced nutation of the Earth: Influence of inner core dynamics: 1. Theory, J. geophys. Res., 96, 8219-8242.
37. Mathews, P.M., Buffett, B.A., Herring, T.A. & Shapiro, I.I., 1991b. Forced nutation of the Earth: Influence of inner core dynamics: 2. Numerical results and comparisons, J. geophys. Res., 96, 8243-8257.
38. Maus, S., Silva, L. & Hulot, G, 2008. Can core-surface flow models be used to improve the forecast of the Earth's main magnetic field?, J. geophys. Res., 113, B08102, doi:.
39. McCarty, D.D. & Babcock, A.K., 1986. The length of day since 1656, Phys. Earth planet. Inter., 44, 281-292.
40. Mound, J.E., 2005. Electromagnetic torques in the core and resonant excitation of decadal polar motion, Geophys. J. Int., 160, 721-728.
41. Munk, W.H. & MacDonald, G.J.F., 1960. The Rotation of the Earth: A Geophysical Discussion, Cambridge University Press, Cambridge
42. Nakada, M., 2003. Core-mantle coupling including a viscoelastic inner core: an application to the axial rotation associated with the Quaternary glacial cycles, Phys. Earth planet. Inter., 138, 289-315.
43. Nakada, M., 2006. Axial and equatorial rotations of the Earth's cores associated with the Quaternary ice age, Phys. Earth planet. Inter., 154, 113-147.
44. Nakada, M., 2008. Long-term true polar wander of the Earth including the effects of convective processes in the mantle and continental drift, Geophys. J. Int., 175, 1235-1244.
45. Nakada, M., 2009, Earth's rotational variations by electromagnetic coupling due to core surface flow on a timescale of ~1 yr for geomagnetic jerk, Geophys. J. Int., 179, 521-535.
46. Nakiboglu, S.M., 1982. Hydrostatic theory of the Earth and its mechanical implications, Phys. Earth planet. Inter., 28, 302-311.
47. Olsen, N., Lühr, H., Sabaka, T.J., Mandea, M., Rother, M., Toffner-Clausen, L. & Choi, S., 2006. CHAOS - a model of the Earth's magnetic field derived from CHAMP, Ørsted, and SAC-C magnetic satellite data, Geophys. J. Int., 166, 67-75.
48. Olsen, N. & Mandea, M., 2007. Investigation of a secular variation impulse using satellite data: the 2003 geomagnetic jerk, Earth planet. Sci. Lett., 255, 94-105.
49. Olsen, N. & Mandea, M., 2008. Rapidly changing flows in the Earth's core, Nat. Geosci., 1, 390-394.
50. Olson, P., Christensen, U. & Glatzmaier, G.A., 1999. Numerical modeling of the geodynamo: mechanism of field generation and equilibration, J. geophys. Res., 104, 10383-10404.
51. Pais, M.A. & Jault, D., 2008. Quasi-geostrophic flows responsible for the secular variation of the Earth's magnetic field, Geophys. J. Int., 173, 421-443.
52. Stacey, F.D., 1992. Physics of the Earth, Brookfield Press, Brisbane, Australia
53. Wardinski, I., Holme, R., Asari, S. & Mandea, M., 2008. The 2003 geomagnetic jerk and its relation to the core surface flows, Earth planet. Sci. Lett., 267, 468-481.