HEPL logo

News & Events


Tuesday June 21, 2011

Fang Fang

Doctoral Candidate
University of Michigan

Simulation of Flux Emergence and Active Region Formation

Abstract: We simulate the buoyant rise of a magnetic flux rope from the solar convection zone into the corona to better understand the energetic coupling of the solar interior to the corona. The magnetohydrodynamic model addresses the physics of radiative cooling, coronal heating and ionization, which allow us to produce a fully realistic model of the solar atmosphere. The simulation illustrates the process by which magnetic flux emerges at the photosphere and and coalesces to form a pair of bipolar sunspots.

We find that the large-scale convective motion in the deep convection zone is critical to form and maintain sunspots, while the horizontal converging flows in the near surface layer prevent the concentrated polarities from separating. The foot points of the sunspots in the convection zone exhibit a coherent rotation motion, resulting in the increasing helicity of the coronal field. Here, the local configuration of the convection causes the convergence of opposite polarities of magnetic flux with a shearing flow along the polarity inversion line. During the rising of the flux rope, the magnetic energy is first injected to above the surface by the emergence, then by the horizontal shearing flow, after which the energy is subducted back to the convection zone by the submerging motion.

Bio: Not Available

Time: 4:00pm – 5:30pm

Location: Physics and Astrophysics Conference Room 102/103

Light refreshments available 4:00pm; Presentation begiins 4:15pm

Open to All