Project Details
Projekt
Numerical dynamo simulations with thermal core-mantle coupling
Applicant
Professor Dr. Ulrich Christensen
Subject Area
Geophysics
Term
from 2000 to 2005
Project identifier
Deutsche Forschungsgemeinschaft (DFG) - Project number 5249650
The Earth`s magnetic field is created by a dynamo process in the outer core, driven by thermal and chemical convection. Recent numerical dynamo simulations can reproduce the main features of the geomagnetic field, for example the dipole dominance, but other important aspects, such as the character of secular variation or field reversals, have not been fully explored. The magnitude and distribution of the heat flow out of the core is controlled by lower mantle structure and dynamics. This thermal coupling to the mantle could lead to long-lived non-zonal structures in the geomagnetic field, preferred paths of the virtual geomagnetic pole during reversals, and may affect the reversal frequency. Previous models that addressed thermal coupling employed simplifying assumptions and covered a restricted parameter range. The aim of this proposal is to explore the role of thermal core-mantle coupling systematically in a fully self-consistent numerical dynamo model. We expect a better understanding of the structure and temporal variation of the geomagnetic field in normal periods and possibly new insights into the mechanism of the reversal process.
DFG Programme
Priority Programmes
