Differences between tangential geostrophy and columnar flow

Geophysical Journal International

Volumn 194, Issue 1, 2013, Pages 145-157

  Amit, Hagay ^a   Pais, Maria Alexandra ^b  

^a UNIVERSITÉ DE NANTES   (France)

^b UNIVERSITY OF COIMBRA   (Portugal)

Author keywords

Dynamo: theories and simulations; Geomagnetic induction; Inverse theory; Rapid time variations; Satellite magnetics

Indexed keywords

DYNAMO: THEORIES AND SIMULATIONS; GEOMAGNETIC INDUCTION; INVERSE THEORY; RAPID TIME VARIATIONS; SATELLITE MAGNETICS;

ELECTRIC GENERATORS; INTERACTIVE DEVICES;

GEOMAGNETISM;

COMPUTER SIMULATION; CORE (PLANETARY); GEODYNAMO; GEOMAGNETIC FIELD; GEOMAGNETISM; SATELLITE IMAGERY; SECULAR VARIATION; TEMPORAL VARIATION; THEORETICAL STUDY;

ATLANTIC OCEAN; INDIA; INDONESIA; PACIFIC OCEAN;

EID: 84879471930     PISSN: 0956540X     EISSN: 1365246X     Source Type: Journal    
DOI: 10.1093/gji/ggt077     Document Type: Article

References (57)

1. Amit, H. &Christensen, U., 2008. Accounting for magnetic diffusion in core flow inversions from geomagnetic secular variation, Geophys. J. Int., 175, 913-924.
2. Amit, H., &Olson, P., 2004. Helical core flow from geomagnetic secular variation, Phys. Earth planet. Inter., 147, 1-25.
3. Amit, H., &Olson, P., 2006. Time-average and time-dependent parts of core flow, Phys. Earth planet. Inter., 155, 120-139.
4. Asari, S.&Lesur,V., 2011. Radial vorticity constraint in core flowmodeling, J. geophys. Res., 116, B11101, doi:10.1029/2011JB008267.
5. Asari, S., Shimizu, H., &Utada, H., 2009. Robust and less robust features in the tangential geostrophy core flows, Geophys. J. Int., 178, 678-692.
6. Aubert, J., 2013. Flow throughout the Earth's core inverted from geomagnetic observations and numerical dynamo models, Geophys. J. Int., 192, 537-556.
7. Aubert, J., &Fournier, A., 2011. Inferring internal properties of Earth's core dynamics and their evolution from surface observations and a numerical geodynamo model, Nonlinear Proc. Geoph., 18, 657-674.
8. Backus, G., 1968. Kinematics of geomagnetic secular variation in a perfectly conducting core, Phil. Trans. R. Soc. Lond. A, 263, 239-266.
9. Backus, G., &LeMouël, 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. astron. Soc., 85, 617-628.
10. Beggan, C., &Whaler, K., 2008. Core flow modelling assumptions, Phys. Earth planet. Inter., 167, 217-222.
11. Bloxham, J., &Jackson, A., 1991. Fluid flow near the surface of the Earth's outer core, Rev. Geophys., 29, 97-120.
12. Busse, F., 1970. Thermal instabilities in rapidly rotating systems, J. Fluid Mech., 44, 441-460.
13. Busse, F., &Carrigan, C.R., 1976. Laboratory simulation of thermal convection in rotating planets and stars, Science, 191, 81-83.
14. Canet, E., Fournier, A., &Jault, D., 2019. Forward and adjoint quasigeostrophic models of the geomagnetic secular variation, J. geophys. Res., 114, doi:10.1029/2008JB006189.
15. Cardin, P.&Olson, P., 1994. Chaotic thermal convection in a rapidly rotating spherical shell: consequences for flow in the outer core, Phys. Earth planet. Inter., 82, 235-259.
16. Christensen,U.&Olson, P., 2003. Secular variation in numerical geodynamo models with lateral variations of boundary heat flow, Phys. Earth planet. Inter., 138, 39-54.
17. Christensen, U., &Wicht, J., 2007. Numerical dynamo simulations, in Treatise on Geophysics. Vol. 8, ed. Olson, P., Elsevier Science, Amsterdam.
18. Chulliat, A., 2004. Geomagnetic secular variation generated by a tangentially geostrophic flow under the frozen-flux assumption-II. Sufficient conditions, Geophys. J. Int., 157, 537-552.
19. Chulliat, A., &Hulot, G., 2000. Local computation of the geostrophic pressure at the top of the core, Phys. Earth planet. Inter., 117, 319-328.
20. Chulliat, A., &Hulot, G., 2001. Geomagnetic secular variation generated by a tangentially geostrophic flow under the frozen-flux assumption-I. Necessary conditions, Geophys. J. Int., 147, 237-246.
21. Eymin, C., &Hulot, G., 2005. On surface core flows inferred from satellite magnetic data, Phys. Earth planet. Inter., 152, 200-220.
22. Finlay, C.C., &Amit, H., 2011. On flow magnitude and field-flow alignment at Earth's core surface, Geophys. J. Int., 186, 175-192.
23. Finlay,C.C., Dumberry,M., Chulliat, A.&Pais,M.A., 2010. Short timescale core dynamics: theory and observations, Space Sci. Rev., 155, 177-218.
24. Finlay, C., Jackson, A., Gillet, N., &Olsen, N., 2012. Core surface magnetic field evolution 2000-2010, Geophys. J. Int., 189, 761-781.
25. Friis-Christensen, E., Lühr, H., &Hulot, G., 2006. Swarm: a constellation to study the Earth's magnetic field, Earth Planets Space, 58, 351-358.
26. Gillet,N., Jault,D.,Canet, E.&Fournier, A., 2010. Fast torsional oscillations and strong magnetic field within the Earth's core, Nature, 465, 74-77.
27. Gillet, N., Pais, M.A., &Jault, D., 2019. Ensemble inversion of time-dependent core flow models, Geochem. Geophys. Geosyst., 10, doi:10.1029/2008GC002290.
28. Gire, C., &LeMouël, J.-L., 1990. Tangentially-geostrophic flow at the coremantle boundary compatible with the observed geomagnetic secular variation: the large-scale component of the flow, Phys. Earth planet. Inter., 59, 259-287.
29. Gubbins, D., 1982. Finding core motions from magnetic observations, Phil. Trans. R. Soc. Lond. A, 306, 249-256.
30. Gubbins, D., 2003. Thermal core-mantle interactions: theory and observations, in Earth's Core: Dynamics, Structure and Rotation, AGU Geodynamics Series, eds Dehant, V., Creager, K., Karato, S., &Zatman, S., American Geophysical Union.
31. Helffrich,G.&Kaneshima, S., 2010. Outer-core compositional stratification from observed core wave speed profiles, Nature, 468, 807-810.
32. Hills, R., 1979. Convection in the Earth's mantle due to viscous shear at the core-mantle interface and due to large-scale buoyancy, PhD thesis, New Mexico State University.
33. Holme, R., 2007. Large-scale flow in the core, in Treatise on Geophysics, Vol. 8, ed. Olson, P., Elsevier Science, Amsterdam.
34. Holme, R., &Whaler, K., 2001. Steady core flow in an azimuthally drifting reference frame, Geophys. J. Int., 145, 560-569.
35. Holme, R., Olsen, N., &Bairstow, F., 2011. Mapping geomagnetic secular variation at the coremantle boundary, Geophys. J. Int., 186, 521-528.
36. Hulot, G., Eymin, C., Langlais, B., Mandea, M., &Olsen, N., 2002. Smallscale structure of the geodynamo inferred from Oersted andMagsat satellite data, Nature, 416, 620-623.
37. Jackson, A., 1997. Time-dependency of tangentially geostrophic core surface motions, Phys. Earth planet. Inter., 103, 293-311.
38. 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. Vol. 12, eds LeMouël, J.-L., Smylie, D.&Herring, T., Geophysical Monograph 72 IUGG, IUGG/AGU, Washington, DC, USA.
39. Jackson, A., Jonkers, A. &Walker,M., 2000. Four centuries of geomagnetic secular variation from historical records, Phil. Trans. R. Soc. Lond., A, 358, 957-990.
40. Jault, D., Gire, C., &LeMouël, J.-L., 1988.Westward drift, core motions and exchanges of angular momentum between core and mantle, Nature, 333, 353-356.
41. LeMouël, J.-L., 1984. Outer core geostrophic flow and secular variation of Earth's magnetic field, Nature, 311, 734-735.
42. Lesur, V., Wardinski, I., Hamoudi, M., &Rother, M., 2010. The second generation of the GFZ Reference Internal Magnetic Model: GRIMM-2, Earth Planets Space, 62, 765-773.
43. Olsen, N., &Mandea, M., 2008. Rapidly changing flows in the Earth's core, Nat. Geosci., 1, 390-394.
44. Olson, P., Christensen, U., &Glatzmaier, G., 1999. Numerical modeling of the geodynamo: mechanisms of field generation and equilibration, J. geophys. Res., 104, 10 383-10 404.
45. Olson, P., Sumita, I., &Aurnou, J., 2002. Diffusive magnetic images of upwelling patterns in the core, J. geophys. Res., 107, doi:10.1029/2001jb000384.
46. Olsen, N., Mandea, M., Sabaka, T., &Tøffner-Clausen, L., 2010. The CHAOS-3 geomagnetic field model and candidates for the 11th generation IGRF, Earth Planets Space, 62, 719-727.
47. Pais, A., &Hulot, G., 2000. 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.
48. 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.
49. Pedlosky, J., 1987. Geophysical Fluid Dynamics. Springer-Verlag, New York, USA.
50. Pozzo,M., Davies, C., Gubbins, D., &Alfè, D., 2012. Thermal and electrical conductivity of iron at Earth's core conditions, Nature, 485, 355-358.
51. Press, W., Flannery, B., Teukolsky, S., &Vetterling, W., 1989. Numerical recipes in Fortran 77. Cambridge University Press, Cambridge, UK.
52. Roberts, P., &Scott, S., 1965. On analysis of the secular variation. 1. A hydromagnetic constraint: theory, J. Geomagn. Geoelectr., 17, 137-151.
53. Schaeffer, N.&Cardin, P., 2005. Quasigeostrophic model of the instabilities of the Stewartson layer in flat and depth-varying containers, Phys. Fluids, 17, 104111, doi:10.1063/1.2073547.
54. Schaeffer, N., &Cardin, P., 2006. Quasigeostrophic kinematic dynamos at low magnetic Prandtl numbers, Earth planet. Sci. Lett., 245, 595-604.
55. Schaeffer,N.&Pais,M.A., 2011. On symmetry and anisotropy of Earth-core flows, Geophys. Res. Lett., 38, L10319, doi:10.1029/2011GL046888.
56. Schubert, G., Turcotte, D., &Olson, P., 2001. Mantle convection in the Earth and planets. Cambridge University Press, Cambridge, UK.
57. Whaler, K., 1980. Does the whole of Earth's core convect?, Nature, 287, 528-530.