Coronal dynamics driven by magnetic flux emergence

Auteurs

• Chen Feng

Paramètres

• Manuels
• Manuels universitaires

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To understand the corona's buildup during active region formation via magnetic flux emergence in the photosphere, we utilize a magnetic flux emergence simulation to drive a magnetohydrodynamics (MHD) simulation for the corona. By properly addressing energy balance, akin to the real corona, our model synthesizes EUV emission that aligns with observations. During the formation of a sunspot pair in the model photosphere, numerous bright coronal EUV loops emerge, rooted at the sunspots' outer edges, where enhanced upward Poynting flux results from the interaction of flows and magnetic field structures. The thermal dynamics and energetics of plasma along individual magnetic field lines align with traditional one-dimensional loop models with prescribed heat input. Although EUV loops are positioned along magnetic field lines at any given time, their temporal evolution can vary significantly. As the footpoints of emerging magnetic field lines traverse regions of increased energy input at the sunspot's edge, a seemingly static EUV structure forms from the plasma in these emerging lines. This model underscores the effectiveness of realistic three-dimensional simulations in replicating features of the actual corona and highlights the critical need to concurrently treat plasma and magnetic fields to accurately model coronal plasma dynamics.

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• Année de publication: 2015