Abstract
A model of three-dimensional self-consistent MHD dynamo in a rotating spherical shell is investigated through numerical simulations, in which a fully spectral scheme is used to guarantee precise computation in space. Generation mechanisms of the magnetic field and the structures of the magnetic and the velocity fields are then examined with emphasis on a fundamental process in the Earth's core. It turns out that the magnetic field is confined in forward convective columns with respect to the drift direction of convection pattern. Detailed examination of generation mechanism of the magnetic field indicates that a strong toroidal magnetic field is generated by shear motion near the equatorial region close to the outer surface, whereas the poloidal magnetic field is rather maintained by fluid motion related to convective columns. Even when the magnetic and the velocity fields vary considerably, this relationship holds with some disruption during disordered states, and time variations of the magnetic field always show a time lag behind those of the velocity field. Although the so-called weak-field regime is investigated, fundamental phenomena shown in this paper should be of importance for understanding of the Earth and planetary dynamo processes.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
