An Ab Initio Approach to the Solar Coronal Heating Problem

Abstract

We approach the solar coronal heating problem ab initio. Starting from a potential extrapolation of a SOHO/MDI magnetogram, a FAL—C atmospheric stratification, and a realistic photospheric velocity field, Spitzer conductivity and magnetic dissipation creates a corona where more than 2 10 6 ergs s —1 cm —2 is dissipated. The winding of the magnetic field by the horizontal velocities in the solar photosphere is sufficient to provide a major part of the heating in the solar corona. The heating is intermittent on the smallest scale, but on average follows the magnetic field strength squared, as is expected from a force free magnetic field configuration. The intermittent heating creates large temperature and density fluctuations in the corona. The total dissipated energy in the corona is at least constant if not increasing with magnetic Reynolds number, making this heating process unavoidable as a major contributor to the heating of the solar corona.