11:29 AM - 11:44 AM
[PEM14-08] Studies on coronal heating by MHD waves by using the RAMENS code
Keywords:Sun, Coronal heating, MHD wave
The temperatures of the solar corona are millions of Kelvins, several hundred times greater than the surface. Over the previous decades, many authors have discussed the coronal heating problem, the fundamental question of how the hot temperatures of the corona are maintained. The heating mechanisms are classified into static "DC" heating and wave-like "AC" heating depending on the timescale of the energy transport into the corona. To study the heating process, some authors have performed "realistic" simulations: radiative magnetohydrodynamic (MHD) simulations treating from the upper convection zone to the corona, including the self-consistent photospheric convection. So far, all realistic simulations have shown that the corona is heated in a DC-like manner. However, their coarse resolutions might suppress the small-scale contributions of MHD waves. Therefore, we study the contribution of MHD waves to the coronal heating by using a realistic simulation with higher resolution. Consequently, we have produced the energy injection from the shear flows within intergranular lanes and the energy cascade in the chromosphere. These processes enhance the high-frequency components of MHD waves penetrating the corona. In addition, we have found that the contribution of the AC heating process can not be qualitatively ignored. Both incompressible and compressible effects work to dissipate the energy of the MHD waves in the corona. It is considered that Alfven wave turbulence (AWT) is the dissipation mechanism of the incompressible waves, and shock dissipation is that of the compressible waves. Our main conclusion is that (1) the chromosphere plays an essential role in the coronal heating, and (2) the AC heating process is likely to contribute to the coronal heating as much as the DC heating processes.