Abstract :
Attention is drawn to a fundamental difference between the mechanisms of the magnetic field freezing in inner layers of the Sun, with isotropic conductivity, and the outer ones, whose conductivity is strongly anisotropic. In the first case, the magnetic field freezing-in is caused by circular induction currents, compensating variations of the magnetic flux through a closed contour bonded to the moving medium. On the other hand, this mechanism evidently cannot work when conductivity is large only along the magnetic field and close to zero in two perpendicular directions. It is shown that the magnetic field freezing in such case is caused by a synchronism of ExB-drift of the plasma particles, resulting from a divergence-free character of the magnetic field and equipotential character of the field lines. The observed distribution of solar plasma parameters shows that a transition between the two kinds of the magnetic field freezing-in corresponds just to the zone of sharp temperature increase in the base of the solar corona. A probable reason for such coincidence is briefly discussed.
