Modelling the generation of magnetic field on the Sun

The magnetic field of the Sun displays a periodic behavior known as the solar cycle. The kinematic αΩ dynamo is the standard theoretical model which adequately reproduces the overall features of this magnetic cycle, such as its period and the latitudinal migration of sunspots. We performed numerical simulations within this theoretical framework. The α coefficient in these simulations contains a nonlinear dependence on the field intensity, which is responsible of the saturation of this dynamo. We obtain a reasonable agreement between our results and several quantitative features observed for the solar cycle. We also performed power spectra of our results and obtain a peak at three times the cycle frequency, in agreement with previous observational studies. We confirm that this peak is a signature of the type of nonlinearity responsible for the saturation mechanism.