Three-dimensional MHD Simulations of emerging flux and associated magnetic reconnection

We present the results of high-resolution three-dimensional MHD simulations of an emerging flux region. The high-resolution simulations that have been enabled by the develpment of high-performance computers have successfully simulated the evolution of fine structure in the global three-dimension dynamics of the emerging flux and magnetic reconnection. It has been found that (1) filamentary structure similar to an arch filament system is spontaneously formed in the emerging flux due to the magnetic Rayleigh-Taylor instability, (2) filamentary current sheets are formed in the emerging flux as a result of the nonlinear development of the magnetic Rayleigh-Taylor instability, and (3) magnetic reconnection between the emerging flux and the coronal field occurs in spatially intermittent way, because of the interchanging of the current sheet due to the magnetic Rayleigh-Taylor instability. Possible observational signatures expected from Solar-B are discussed.