The Rikitake model arose from the study of two connected identical frictionless disk dynamos, where reversals of electric current and magnetic field are observed. An analogous model is proposed to explain the highly irregular reversals of the Earth’s magnetic ﬁeld over geological history.
The original equations describing the system are given by: , , , , where and are the selfinductances of the coils, and are the resistances, and are the electric currents, and are the angular velocities, and are the moments of inertia, and and are the driving forces. and making the substitutions with the parameter , we obtain , , . The Rikitake system exhibits Lorenztype chaos while orbiting around two unstable ﬁxed points. [1] T. Rikitake, "Oscillations of a System of Disk Dynamos," Mathematical Proceedings of the Cambridge Philosophical Society, 54(1), 1958 pp. 89–105. doi: 10.1017/S0305004100033223. [2] J. A. Jacobs, Reversals of Earth's Magnetic Field, New York: Cambridge University Press, 1994.
