Nonlinear Processes in Geophysics www.nonlin-processes-geophys.net 1023-5809 1607-7946 13 5 2006 10.5194/npg-13-525-2006 http://www.nonlin-processes-geophys.net/13/525/2006/ http://www.nonlin-processes-geophys.net/13/525/2006/npg-13-525-2006.html http://www.nonlin-processes-geophys.net/13/525/2006/npg-13-525-2006.pdf 525 529 2006-10-04 On effect of precession-induced flows in the liquid core for early Earth's history S. L. Shalimov shalimov@ifz.ru Institute of Physics of the Earth, Moscow, Russia Space Research Institute, Moscow, Russia Secondary and tertiary flow patterns seen in experiments simulating flow in the Earth's liquid core induced by luni-solar precession of the solid mantle (Vanyo et al., 1995) hint at the development of non-axisymmetric columnar periodic structures. A simple interpretation of the structure formation is presented in a hydrodynamic approach. It is suggested that if similar flow patterns can occur in the Earth's liquid core enclosed into precessing and rotating mantle then kinematic of the flows may be regarded as a possible geodynamo mechanism for early Earth's history (before the solid core formation). Busse, F. H.: Steady fluid flow in a precessing spheroidal shell, J. Fluid. Mech., 33, 739–751, 1968. Busse, F. H.: Thermal instabilities in rapidly rotating systems, J. Fluid. Mech., 44, 441–460, 1970. Channell, J. E. T., Hodel, D. A., McManus, J., and Lehman, B.: Orbital modulation of the Earth's magnetic field intensity, Nature, 394, 464–468, 1998. Dolginov, Sh. Sh.: Precession of planets and generation of their magnetic fields, Geomagnetism and Aeronomy (in Russian), 35, 1–29, 1995. Gubbins, D., Alfe, D., Masters, G., et al.: Can the Earth's dynamo run on heat alone?, Geophys. J. Int., 155, 609–622, 2003. Hasegawa, A.: Self organization processes in continuous media, Adv. Phys., 34, 1–42, 1985. Howard, L. W.: Neutral curves and stability boundaries in stratified flows, J. Fluid. Mech., 16, 333–342, 1963. Jones, C. A.: Convection-driven geodynamo models, Phil. Trans. R. Soc. London, A358, 873–884, 2000. Kageyama, A. and Sato, T.: Generation mechanism of a dipole field by a magnetohydrodynamic dynamo, Phys. Rev. E., 55, 4617–4626, 1997. Kerswell, R. R.: The instability of precessing flow, Geophys. Astrophys. Fluid Dyn., 72, 107–144, 1993. Kerswell, R. R.: Upper bounds on the energy dissipation in turbulent precession, J. Fluid. Mech., 321, 335–370, 1996. Labrosse, S.: Thermal and magnetic evolution of the Earth's core, PEPI, 140, 127–143, 2003. Loper, D.: Torque balance and energy budget for the precessionally driven dynamo, PEPI, 11, 43–60, 1975. Malkus, V. W. R.: Precession of the Earth as a cause of geomagnetism, Science, 160, 259–264, 1968. McElhinny, M. W. and Senanayake, W. E.: Paleomagnetic evidence for the existence of the geomagnetic field 3.5 Ga ago, J. Geophys. Res., 85, 3523–3528, 1980. Nimmo, F., Price, G. D., Brodholt J., and Gubbins, D.: The influence of potassium on core and geodynamo evolution, Geophys. J. Int., 156, 363–376, 2004. Pedlosky, J.: Geophysical Fluid Dynamics, Springer-Verlag, New York, 1982. Poincare, H.: Sur la precession des corps deformables, Bull. Astron., 27, 321–356, 1910. Reshetnyak, M. Yu.: Dynamo catastrophe, or why geomagnetic field exists so long?, Geomag. Aeronom. (in Russian), 45, 571–575, 2005. Rochester, M. G., Jacobs, J. A., Smylie, D. E., and Chong, K. F.: Can precession power the geomagnetic dynamo?, Geophys. J. R. Astr. Soc., 43, 661–678, 1975. Shalimov, S. L.: On instability of geomagnetic field, Dokl. Akad. Nauk (in Russian), 395, 258–260, 2004. Sloudsky, Th.: De la rotation de la terre suppose fluide a son interieur, Bull. De la Soc. Impeiale des Naturalistes., 9, 285–318, 1985. Stewartson, K. and Roberts, P. H.: On the motion of a liquid in a spheroidal cavity of a precessing rigid body, J. Fluid Mech., 17, 1–20, 1963. Tilgner, A.: Precession driven dynamos, Phys. Fluids, 17, 034104-1-034104-6, 2005. Vanyo, J., Wilde, P., Cardin, P., and Olson, P.: Experiments on precessing flows in the Earth's liquid core, Geophys. J. Int., 121, 136–142, 1995. Vanyo, J. and Dunn, J. R.: Core precession: flow structures and energy, Geophys. J. Int., 142, 409–425, 2000.