The solar magnetic field drives a wide range of phenomena, from sunspots to flares and coronal mass ejections. This field is maintained against ohmic dissipation by means of a hydromagnetic dynamo. In recent years, evidence has accumulated in support of a particular family of dynamo models, Babcock-Leighton models, where the surface fields play a key role. Specifically, the surface transport of magnetic flux coming from emerged regions regenerates the global dipole field, which is the source of the subsurface toroidal field for the next cycle. Many global dynamo models rely on the approxima...
