Determination of a steady velocity field in a rotating frame of reference at the surface of the Earth's core

Geophysical Journal International

Volumn 126, Issue 1, 1996, Pages 92-100

  Davis, R G ^a,b   Whaler, K A ^a  

^a UNIVERSITY OF EDINBURGH   (United Kingdom)

^b UNIVERSITY OF BAYREUTH   (Germany)

Author keywords

Core mantle boundary; Flow imaging; Geomagnetism

Indexed keywords

CONVECTION; CORE/MANTLE BOUNDARY; FLOW IMAGING; GEOMAGNETISM; SECULAR VARIATION; STEADY VELOCITY FIELD;

EID: 0030445743     PISSN: 0956540X     EISSN: None     Source Type: Journal    
DOI: 10.1111/j.1365-246X.1996.tb05269.x     Document Type: Article

References (45)

1. Backus, G.E., 1968. Kinematics of secular variation in a perfectly conducting core, Phil. Trans. R. Soc. Lond., A, 263, 239-266.
2. Backus, G.E. & Le Mouél, J.L., 1986. The region on the core-mantle boundary where a geostrophic velocity field can be determined from frozen flux magnetic data, Geophys. J. R. astr. Soc., 85, 617-628.
3. Benton, E.R. & Whaler, K.A., 1983. Rapid diffusion of the poloidal magnetic field through the weakly conducting mantle: a perturbation solution. Geophys. J. R. astr. Soc., 75, 77-100.
4. Bloxham, J., 1987. Simultaneous stochastic inversion for geomagnetic main field and secular variation I: a large scale inverse problem, J. geophys. Res., 91, 11 597-11 608.
5. Bloxham, J., 1988a. The dynamical regime of fluid flow at the core-mantle boundary, Geophys. Res. Lett., 15, 585-588.
6. Bloxham, J., 1988b. The determination of fluid flow at the core surface from geomagnetic observations, in Mathematical Geophysics, pp. 189-208, eds Vlaar, J.J., Nolet, G., Wortel, M.J.R. & Cloetingh, S.A.P.L. Reidel, Dordrect.
7. Bloxham, J., 1989. Simple models of fluid flow at the core surface derived from geomagnetic field models, Geophys. J. Int., 99, 173-182.
8. Bloxham, J., 1992. The steady part of the secular variation of the Earth's magnetic field, J. geophys. Res., 97, 19 565-19 579.
9. Bloxham, J. & Gubbins, D., 1987. Thermal core-mantle interactions, Nature, 325, 511-513.
10. Bloxham, J. & Jackson, A., 1989. Simultaneous stochastic inversion for geomagnetic main field and secular variation II: 1820-1980, J. geophys. Res., 94, 15 753-15 769.
11. Bloxham, J. & Jackson, A., 1990. Lateral temperature variations at the core-mantle boundary deduced from the magnetic field, Geophys. Res. Lett., 17, 1997-2000.
12. Bloxham, J. & Jackson, A., 1991. Fluid flow near the surface of Earth's outer core, Rev. Geophys., 29, 97-120.
13. Bloxham, J. & Jackson, A., 1992. Time-dependent mapping of the magnetic field at the core-mantle boundary, J. geophys. Res., 97, 19 537-19 563.
14. Bloxham, J., Gubbins, D. & Jackson, A., 1989. Geomagnetic secular variation, Phil. Trans. R. Soc. Lond., A. 392, 415-502.
15. Bullard, E.C., & Gellman, H., 1954. Homogeneous dynamos and terrestrial magnetic, Phil. Trans. R. Soc. Lond., A, 247, 213-278.
16. Courtillot, V. & Le Mouël, J.L., 1988. Time variations of the Earth's magnetic field: from daily to secular, Ann. Rev. Earth planet. Sci., 16, 389-476.
17. Davis, R.G. & Whaler, K.A., 1992. Velocity fields at the Earth's core surface from 1900 to 1980 using the frozen-flux approximation and steady velocity assumption, Geophys. astrophys. Fluid Dyn., 141, 241-259.
18. Ducruix, J., Gire, C. & Le Mouël, J.L., 1983. Exsisitence et caractére planétaire d'une secousse de la variaition séculaire du champ géomagnétique en 1912 1913, C.R. Acad. Sci., Ser B, 296, 1419-1424.
19. Gubbins, D., 1982. Finding core motions from geomagnetic observations, Phil. Trans. R. Soc. Lond., A, 306, 247-254.
20. Gubbins, D., 1983. Geomagnetic field analysis - I. Stochastic inversion, Geophys. J. R. astr. Soc., 73, 641-672.
21. Gubbins, D. 1989. Implications of geomagnetism for mantle structure, Phil. Trans. R. Soc. Lond., A, 328, 363-375.
22. Gubbins, D. & Bloxham, J., 1985. Geomagnetic field analysis - III. Magnetic fields at the core-mantle boundary, Geophys. J. R. astr. Soc., 80, 695-713.
23. Gubbins, D. & Bloxham, J., 1987. Morphology of the geomagnetic field and implications for the geodynamo, Nature, 325, 509-511.
24. Gubbins, D. & Roberts, P.H., 1978. Magnetohydrodynamics of the Earth's core, in Geomagnetism, Vol. 2, pp. 1-183, ed. Jacobs, J.A., Academic Press, London.
25. Hide, R. & Stewartson, K., 1972. Hydromagnetic oscillations of the Earth's core, Rev. Geophys., 10, 579-598.
26. Hills, R.G., 1979. Convection in the Earth's mantle due to viscous shear at the core-mantle interface and due to large scale buoyancy, PhD thesis, N.M. State Univ., USA.
27. Jackson, A. & Bloxham, J., 1991. Mapping the fluid flow and shear near the core surface using the radial and horizontal components of the magnetic field, Geophys. J. Int., 105, 199-211
28. Jackson, A., Bloxham, J. & Gubbins, D., 1993. Time-dependent flow at the core surface and conservation of angular momentum in the coupled core-mantle system, in Dynamics of Earth's deep interior and Earth rotation, eds. LeMouël, J.L., Smylie, D.E. & Herring, T., Geophysical Monograph, 72.
29. Kahle, A.B., Vestine, E.H. & Ball, R.H., 1967. Estimated surface motions of the Earth's core. J. geophys. Res., 72, 1095-1108.
30. Kohler, M.D. & Stevenson, D.J., 1990. Modelling 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.
31. Le Mouël, J.L., Gire, C. & Madden, T., 1985. Motions at the core surface to the geostrophic approximation, Phys. Earth planet. Inter., 39, 270-287.
32. Lloyd, D. & Gubbins, D., 1990. Toroidal fluid motion at the top of the Earth's core, Geophys. J. Int., 100, 455-467.
33. Roberts, P.H. & Scott, S., 1965. On the analysis of the the secular variation, I, a hydrodynamic constraint: theory, J. Geomagn. Geoelect., 17, 137-151.
34. Voorhies, C.V., 1984. Magnetic location of Earth's core-mantle boundary and estimates of adjacent fluid motion, PhD thesis, University of Colorado, USA.
35. Voorhies, C.V., 1986a. Steady flows at the top of the Earth's core derived from geomagnetic field models, J. geophys. Res., 91, 12 444-12 466.
36. Voorhies, C.V., 1986b. Steady surfical core flows: an alternate method, Geophys. Res. Lett., 13, 1537-1540.
37. Voorhies, C.V., 1993. Geomagnetic estimates of steady surfical core flow and flux diffusion: unexpected geodynamo experiments, in Dynamics of Earth's deep interior and Earth rotation, eds Mouël, J.L., Smylie, D.E. & Herring, T., Geophysical Monograph, 72, 113-127.
38. Voorhies, C.V. & Backus, G., 1985. Steady flows at the top of the Earth's core from geomagnetic models: The steady motions theorem, mantle, J. geophys. Res., 99, 6685-6693.
39. Whaler, K.A., 1980. Does the whole of the Earth's core convect? Nature, 287, 528-530.
40. Whaler, K.A., 1986. Geomagnetic evidence for fluid upwelling at the core-mantle boundary, Geophys. J. R. astr. Soc., 86, 563-588.
41. Whaler, K.A. & Clarke, S.O., 1988. A steady velocity field at the top of the Earth's core in the frozen flux approximation, Geophys. J. Int., 94, 143-155.
42. Whaler, K.A. & Davis, R.G., 1996. Probing the Earth's core with geomagnetism, in Earth's Deep Interior, ed. Crossley, D., Gordon & Breach, New York, in press.
43. Zhang, K. & Busse, F.H., 1990. Generation of magnetic fields by convection in a rotating spherical fluid shell of infinite Prandtl number, Phys. Earth planet. Inter., 59, 208-222.
44. Zhang, K. & Gubbins, D., 1992. Convection in the Earth's core driven by lateral temperature variations in the lower mantle, Geophys. J. Int., 108, 247-255.
45. Zhang, K. & Gubbins, D., 1993. Convection in a rotating spherical fluid shell with an inhomogeneous boundary condition at infinite Prandtl number, J. Fluid Mech., 250, 209-232.