Data-driven magnetohydrodynamic model for active region evolution

We present a self-consistent, three-dimensional, magnetohydrodynamics model together with time-dependent boundary conditions based on the projected method of characteristics at the source surface (photosphere) to accommodate the observations. The new physics included in this model are differential rotation, meridional flow, effective diffusion, and cyclonic turbulence effects in which the complex magnetic field structure can be generated through the nonlinear interaction between the plasma and magnetic field. This solution, again, is accomplished by including the time-dependent boundary conditions derived from the method of characteristics. This procedure is able to accommodate observations via self-consistent and appropriate data inputs to the boundary. Thus, subphotospheric (i.e., convective zone) effects, through observations, are able to be coupled with the corona. To illustrate this new model, we have employed an observed active region's (NOAA AR 8100) magnetic field measurements from SOHO MDI magnetograms to demonstrate the model's capability. Thus, the evolution of three-dimensional magnetic field, velocity field, and energy transport are shown, thereby enabling us to study the physical mechanisms of AR evolution.