Earth's Core and the Geodynamo
Bruce A. Buffett
Earth's magnetic field is generated by fluid motion
in the liquid iron core. Details of how this occurs are now emerging
from numerical simulations that achieve a self-sustaining magnetic field. Early results predict a dominant dipole field outside the core,
and some models even reproduce magnetic reversals. The simulations also
show how different patterns of flow can produce similar external fields. Efforts to distinguish between the various possibilities appeal
to observations of the time-dependent behavior of the field. Important
constraints will come from geological records of the magnetic field in
the past.
Department of Earth and Ocean Sciences, University of British
Columbia, 2219 Main Mall, Vancouver, BC, Canada V6T 1Z4. E-mail:
buffett{at}eos.ubc.ca