Numerical simulations of large-scale solar magnetic fields

A transport equation which describes the evolution of the large-scale magnetic field of the sun was solved numerically. Data derived from solar magnetic observations are used to initialize the computations and to account for the emergence of new magnetic flux during the sunspot cycle. The objective is to assess the ability of the model to reproduce the observed evolution of the field patterns. Recent results from simulations of individual active regions over a few solar rotations and of the magnetic field of the sun over sunspot cycle 21 are discussed.