The Simulation of Dynamos on Massive Parallel Computers

摘要

The goal of geophysics is to develop an understanding of the processes taking place in the Earth's interior. An important part of this is the development of a model of the Earth's magnetic field that can reproduce its features. Since seismology showed that the Earth's outer core is liquid and mineral physics demonstrated that the outer core mainly consists of iron, the concept of a self-exciting dynamo has been accepted as the mechanism behind the Earth's magnetic field. The idea behind the geobdynamo is that flow of a conducting fluid in the outer core maintains a magnetic field which would otherwise decay due to electrical resistance. This flow maintaining the dynamo is driven by density variations due to thermal and compositional differences. Not only electromagnetic forces and buoyancy forces play a role in this process but also Coriolis forces due to the strong rotation of the Earth's outer core. Due to the fact that a fine resolution is needed because of the small scale phenomena which are present in the solution and due to the fact that long time integrations are necessary, a massive parallel computer is an indispensable research tool in this area.