DEVELOPMENT OF MAGNETOHYDRODYNAMIC TURBULENCE IN CORONAL LOOPS

We propose that a stationary spectrum of magnetohydrodynamic turbulence is generated in solar coronal loops by the interweaving of magnetic field lines driven by the turbulent velocity field in the convective region. Starting from the set of incompressible magnetohydrodynamic equations, we derive two ordinary differential equations describing the stationary turbulent energy spectrum and the frequency of direct energy cascade for a given kinetic energy spectrum of the subphotospheric convective motions. We obtain an estimate of the typical dissipation length scale, at which magnetic energy efficiently heats the plasma by Joule dissipation. The impact of recent results of two-dimensional magnetohydrodynamic numerical simulations on the coronal heating problem is also discussed.