A Numerical Study of Long-Range Magnetic Impacts During Coronal Mass Ejections

Abstract

With the global view and high-cadence observations from Solar Dynamics Observatory/Atmospheric Imaging Assembly and Solar TErrestrial RElations Observatory, many spatially separated solar eruptive events appear to be coupled. However, the mechanisms for "sympathetic" events are still largely unknown. In this study, we investigate the impact of an erupting flux rope on surrounding solar structures through large-scale magnetic coupling. We build a realistic environment of the solar corona on 2011 February 15 using a global magnetohydrodynamics model and initiate coronal mass ejections (CMEs) in active region 11158 by inserting Gibson-Low analytical flux ropes. We show that a CME's impact on the surrounding structures depends not only on the magnetic strength of these structures and their distance to the source region, but also on the interaction between the CME and the large-scale magnetic field. Within the CME expansion domain where the flux rope field directly interacts with the solar structures, expansion-induced reconnection often modifies the overlying field, thereby increasing the decay index. This effect may provide a primary coupling mechanism underlying the sympathetic eruptions. The magnitude of the impact is found to depend on the orientation of the erupting flux rope, with the largest impacts occurring when the flux rope is favorably oriented for reconnecting with the surrounding regions. Outside the CME expansion domain, the influence of the CME is mainly through field line compression or post-eruption relaxation. Based on our numerical experiments, we discuss a way to quantify the eruption impact, which could be useful for forecasting purposes.

The Possible Impact of L5 Magnetograms on Non-Potential Solar Coronal Magnetic Field Simulations

“…It also indicates that potential field extrapolations may be unreliable as the basis for solar wind models such as the Wang-Sheeley-Arge model (Wang & Sheeley 1990a,b, 1992Arge & Pizzo 1999Arge et al 2003). Additionally, such long-range connections could be important for triggering socalled sympathetic flares and eruptions (Schrijver et al 2013;Jin et al 2016).…”

K2 Ultracool Dwarfs Survey. II. The White Light Flare Rate of Young Brown Dwarfs

“…Tests of Uchidas predictions have been provided by observations (e.g. Shen et al 2013) and modelling (e.g, Steinolfson & Mullan 1980,Jin et al 2016) of fast-mode waves propagating through a variety of structures in the solar corona. However, the tests mentioned in the preceding sentence were based on indirect inferences of the v A value in different regions of the Sun.…”

“…But in the case of AR-B, the fast-mode wave will be refracted into the AR, thereby having a chance to perturb the plasma inside AR-B, perhaps enough to initiate a flare. In this scenario, a SF is more likely to occur in an AR with a small value v A : or, in the terminology of Jin et al (2016), the "impact" of the wave on AR-B (with its lower v A ) would be larger. What might cause the v A value in AR-B to be smaller?…”

CHROMOSPHERE TO 1 au SIMULATION OF THE 2011 MARCH 7th EVENT: A COMPREHENSIVE STUDY OF CORONAL MASS EJECTION PROPAGATION

“…For the flux-emergence model, CMEs are triggered by Lorentz-force-driven shearing motions that transport axial flux and energy to the expanding field (e.g., Manchester et al 2004a). All three initiation models have been successfully used in CME simulations (e.g., Manchester et al 2004b,c;Roussev et al 2004;Manchester et al 2008;MacNeice et al 2004;van der Holst et al 2009;Karpen et al 2012;Manchester et al 2014;Jin et al 2016a). …”