The boundary radial component is identical among the four panels. The blue (red) colors on the sphere in each panel indicate the positive (negative) radial component of the boundary magnetic field. Panels (b) and (c) are those obtained with the boundary treatment with the switching. Panel (d) is from the “full” E-driven simulation.
Panel (a) shows the (quasi-)steady state from the conventional method. In our E-driven simulation model, a set of special boundary treatments is needed for properly handling the horizontal (latitudinal and longitudinal) components of the specified boundary magnetic field.įigure 1| (Time-relaxed states of the solar corona at CR2106, as an example. As a natural consequence, we can obtain the nonpotential coronal magnetic features matching the solar-surface observations. By driving the simulated global solar corona with the curl of electric field, the divergence-free condition of the magnetic field can be preserved and the boundary values of the magnetic field can evolve as specified.
In this model (hereafter called E-driven model), the simulated corona can be driven with electric field, whose curl fully matches the temporal variations of the full three-component magnetic field on the photosphere as observed. Recently, we developed a new MHD simulation model for the global corona. For the global coronal models, three-component vector synoptic maps from the SDO/HMI are available at the JSOC database. An advance of this simulation approach, like the capability of reproducing highly nonpotential magnetic features, can be achieved by using the three-component vector magnetic-field data from the polarimetry observations. In this simulation strategy, the whole-Sun synoptic map data of the line-of-sight (LoS) magnetogram observation have been used to specify the solar-surface boundary values in the simulation and to determine the initial potential field. Magnetohydrodynamics (MHD) simulation can numerically reproduce three-dimensional structures of the coronal magnetic field and plasma.
College of Science, George Mason University