MHD Simulation of the 13 December 2006 Eruptive Flare of AR10930

Abstract:

We present an MHD simulation of the initiation of the coronal mass ejection (CME) on 13 December 2006 in the emerging δ-sunspot active region NOAA 10930. We have improved upon a previous simulation by Fan (2016) in the following ways: (1) Incorporate an ambient solar wind instead of using a static potential magnetic field extrapolation as the initial state; (2) In addition to imposing the emergence of a twisted flux rope at the lower boundary to build up the pre-eruption field, also impose at the lower boundary a random electric field that represents the effect of turbulent convection that drives field-line braiding and the resultant resistive heating in the corona. With the inclusion of this heating, which depends on the magnetic field topology, we are able to model the synthetic soft X-ray emissions produced by the coronal loops. We find that the simulated pre-eruption active region magnetic field, where a twisted magnetic flux rope is built up due to the flux emergence, produces synthetic soft X-ray emission that shows qualitatively similar morphology as the observed X-ray image by the Hinode/XRT, with the formation of an inverse-S shaped “sigmoid” that sharpens at the onset of eruption. It is found that the rotation and expansion of the erupting flux rope is significantly affected by the two fast solar wind streams adjacent to the active region.