A Self-consistent Turbulent Model for Solar Coronal Heating

The rate of solar coronal heating induced by the slow random motions of the dense photosphere is calculated in the framework of an essentially parameter-free model. This model assumes that these motions maintain the corona in a state of small-scale MHD turbulence. The associated dissipative effects then allow a large-scale stationary state to be established. The solution for the macroscopic coronal flow and the heating flux is first obtained assuming the effective (turbulent) dissipation coefficients to be known. In a second step these coefficients are calculated by the self-consistency argument that they should result from the level of turbulence associated with this very heating flux. For the sake of tractability the derivation is restricted to a two-dimensional situation where boundary flows are translationally symmetric. The resulting value of the heating rate and the predicted level of microturbulent velocity compare satisfactorily with the observational data.