We use numerical simulations of a well-known phase-transition model to study reversals of the geomagnetic field. Each ring current in the geodynamo was supposed to behave as a magnetic spin while the magnetization of the model was supposed to be proportional to the Earth's magnetic dipole. We have performed a size-dependence study of the calculated quantities. Power laws were obtained for the distribution of times between reversals. Some of our results are closer to actual ones than the corresponding to previous simulations. For the largest systems that we have simulated the exponent of the power law tends towards values very near -1.5, generally accepted as the right value for this phenomenon. Some possible trends for future works are advanced.
Ising model; Reversals; Computer simulation
