  We study interacting classical magnetic and pseudoscalar fields in frames of
the axion electrodynamics. A large scale pseudoscalar field can be the coherent
superposition of axions or axion like particles. We consider the evolution of
these fields in a thin spherical layer. Decomposing the magnetic field into the
poloidal and toroidal components, we take into account their symmetry
properties. The dependence of the pseudoscalar field on the latitude is
accounted for the induction equation. Then, we derive the dynamo equations in
the low mode approximation. The nonlinear evolution equations for the harmonics
of the magnetic and pseudoscalar fields are solved numerically. As an
application, we consider a dense axion star embedded in solar plasma. The
behavior of the harmonics and their typical oscillations frequencies are
obtained. We suggest that such small objects consisting of axions and confined
magnetic fields can cause the recently observed flashes in solar corona
contributing to its heating.
