Oscillating dynamo in the presence of a fossil magnetic field. The solar cycle

Hydrodynamic dynamo generation of oscillating magnetic fields in the presence of an external, ambient magnetic field introduces a marked polarity asymmetry between the two halves of the magnetic cycle. The principle of oscillating dynamo interaction with external fields is developed, and a tentative application to the Sun is described. In the Sun a dipole moment associated with the stable fluid beneath the convection zone would produce an asymmetrical solar cycle