Theory and Transport of Nearly Incompressible Magnetohydrodynamic Turbulence. IV. Solar Coronal Turbulence

A new model describing the transport and evolution of turbulence in the quiet solar corona is presented. In the low plasma beta environment, transverse photospheric convective fluid motions drive predominantly quasi-2D (nonpropagating) turbulence in the mixed-polarity "magnetic carpet," together with a minority slab (Alfvenic) component. We use a simplified sub-Alfvenic flow velocity profile to solve transport equations describing the evolution and dissipation of turbulence from 1 to 15 R-circle dot (including the Alfven surface). Typical coronal base parameters are used, although one model uses correlation lengths derived observationally by Abramenko et al., and the other assumes values 10 times larger. The model predicts that (1) the majority quasi-2D turbulence evolves from a balanced state at the coronal base to an imbalanced state, with outward fluctuations dominating, at and beyond the Alfven surface, i.e., inward turbulent fluctuations are dissipated preferentially; (2) the initially imbalanced slab component remains imbalanced throughout the solar corona, being dominated by outwardly propagating Alfven waves, and wave reflection is weak; (3) quasi-2D turbulence becomes increasingly magnetized, and beyond similar to 6 R-circle dot, the kinetic energy is mainly in slab fluctuations; (4) there is no accumulation of inward energy at the Alfven surface; (5) inertial range quasi-2D rather than slab fluctuations are preferentially dissipated within similar to 3 R-circle dot; and (6) turbulent dissipation of quasi-2D fluctuations is sufficient to heat the corona to temperatures similar to 2 x 10(6) K within 2 R-circle dot, consistent with observations that suggest that the fast solar wind is accelerated most efficiently between similar to 2 and 4 R-circle dot.