HR: 14:50h
AN: GP23A-05 INVITED    [Abstracts]
TI: Understanding Core-Mantle Coupling Through Dynamo Models
AU: * Sreenivasan, B
EM: binod@earth.leeds.ac.uk
AF: School of Earth and Environment, University of Leeds, United Kingdom., School of Earth and Environment, University of Leeds, Leeds, LS2 9JT, United Kingdom
AB: Core-mantle interaction in the Earth is studied using convection-driven dynamo models. We begin by considering an idealized regime that supports locking of the fluid motion and magnetic field to external inhomogeneities. In perfect locking, the azimuthal velocity in the fluid core has the profile of a thermal wind imposed by the boundary. In strongly convective dynamos, the competition between buoyancy-driven and boundary-driven thermal winds determines the extent of fluid-boundary coupling. We go on to show that dynamos with weakly convecting outer layers support locking, whereas strongly convecting outer regions swamp any influence of the lateral variations at the boundary. Finally, we investigate the tomographic boundary condition to see how its individual harmonic components may affect the morphology of the geomagnetic field.
UR: http://earth.leeds.ac.uk/~earbs
DE: 1507 Core processes (1213, 8115)
DE: 1510 Dynamo: theories and simulations
SC: Geomagnetism and Paleomagnetism [GP]
MN: 2007 Fall Meeting