Gary A Glatzmaier, University of California, Santa Cruz

We illustrate the three-dimensional structure of the simulated geomagnetic field generated in the Earth's convecting fluid core. Our geodynamo simulations now span more than a million years, using an average computational time step of about 15 days. At the surface of our model Earth, the simulated magnetic field has an intensity, an axial dipole dominated structure, and a westward drift of the non-dipolar structure that are all similar to the Earth's. In addition, several spontaneous reversals of the magnetic dipole polarity have occurred during our simulations, similar to those seen in the Earth's paleomagnetic record.