Title and Abstract

Title:   Simulations and Observations of Active Region Magnetic Flux Emergence

Abstract:   We show observations and simulations of active regions during periods of magnetic flux emergence and focus our study on the buildup free magnetic energy that drives solar eruptions. To examine the energy buildup process, we developed a new model of the near surface convection zone constructed on an adaptive spherical grid.  The Spherical Wedge Active Region Model (SWARM) simulates flux emerging on an active region scale extending from a depth of 35 Mm and extending 150x300 Mm in horizontal directions.  Here, we show results of a twisted flux rope emerging through the hierarchy of granular convection, and examine the flow patterns that arise as the flux approaches the photosphere. We find energy buildup resulting from shearing, rotating and converging flows that combine to concentrate free magnetic energy along the polarity inversion line of the simulated active region.  Shear and rotational flows are a consequence of the Lorentz force that develops from a complex interaction between magnetic fields and the thermal pressure of the Sun's gravitationally stratified atmosphere.  These flows transport magnetic flux and energy from the submerged portion of the field to the corona providing the necessary energy for flares, filament eruptions and CMEs.