Solar Surface Anisotropy effect on the Magnetic Field

摘要

Within the literature there are at least 15 references indicating that the horizontal magnetic flux does not exactly balance vertical flux in sunspots, leading to the surprising result that div {→ under letter B} would depart from zero. Intuitively, this has to be related to the stratification at the surface of the star, due to which horizontal and vertical typical lengths are different. This surface anisotropy results from gravity, but how does gravity influence the magnetic field? To answer this question, a scenario has been proposed in two recent publications, based on anisotropic Debye shielding. The presentation reported in this paper was devoted to investigate the possibility and causes of a non-zero div {→ under letter B}. A scaling law associated with the anisotropy is able to reestablish the nullity of div {→ under letter B}, which would lead to a renewed MHD in the solar photosphere layer. An eventual observation in the laboratory is also reported.