"The Rikitake chaotic dynamical system is a model which attempts to explain the irregular polarity switching of the geomagnetic field. The system exhibits Lorenz-type chaos and orbiting around two unstable fixed points. It describes the currents of two coupled dynamo disks."

Rikitake Attractor and It's Synchronization Application for Secure Communication Systems
Chaos and geomagnetic reversals

This WebGL visualization with half a million particles was made by Flexi23.
shoutouts to @notlion and @BlurSpline