Sympathetic Magnetic Breakout Coronal Mass Ejections From Pseudostreamers

Abstract

We present high resolution 2.5-dimensional MHD simulation results of magnetic breakout-initiated coronal mass ejections (CMEs) originating from a coronal pseudostreamer configuration. The coronal null point in the magnetic topology of pseudostreamers means the initiation of consecutive sympathetic eruptions is a natural consequence of the system's evolution. A generic source region energization process -ideal footpoint shearing parallel to the pseudostreamer arcade polarity inversion lines -is all that is necessary to store sufficient magnetic energy to power consecutive CME eruptions given that the pseudostreamer topology enables the breakout initiation mechanism. The second CME occurs because the eruptive flare reconnection of the first CME simultaneously acts as the overlying pre-eruption breakout reconnection for the sympathetic eruption. We examine the details of the magnetic and kinetic energy evolution and the signatures of the overlying null point distortion, current sheet formation, and magnetic breakout reconnection giving rise to the runaway expansion that drives the flare reconnection below the erupting sheared field core. The numerical simulation's spatial resolution and output cadence are sufficient to resolve the formation of magnetic islands during the reconnection process in both the breakout and eruptive flare current sheets. We quantify the flux transfer between the pseudostreamer arcades and show the eruptive flare reconnection processes flux ∼10 times faster than the pre-eruption breakout reconnection. We show that the breakout reconnection jets cause bursty, intermittent upflows along the pseudostreamer stalk as well as downflows in the adjacent pseudostreamer arcade, both of which may be observable as pre-eruption signatures. Finally, we examine the flux rope CME -2trajectories and show that the breakout current sheet provides a path of least resistance as an imbalance in the surrounding magnetic energy density and results in a non-radial CME deflection early in the eruption.

The physical mechanisms that initiate and drive solar eruptions

“…191 of interacting active regions (Jacobs et al 2009), and possibly to trigger sympathetic eruptions in models where several current-carrying flux tubes are included (Török et al 2011;Lynch & Edmondson 2013), in line with the concept proposed by Schrijver & Title (2011) and further developed by Schrijver et al (2013).…”

“…Full simulations of the breakout were first achieved in 2.5D MHD simulations (MacNeice et al 2004), including with very high spatial resolutions (Karpen et al 2012;Lynch & Edmondson 2013) and with the solar wind (van der Holst et al 2007;Masson et al 2013). A key difference with the tether-cutting model, though, is that the breakout was also found to occur in a 3D line-tied simulation (Lynch et al 2008), and very probably in a 3D flux emergence simulation (Archontis & Török 2008).…”

The Causes of Quasi-homologous CMEs

“…The flux rope outside expands and erupts as the first CME, causing a breakout reconnection above one of the flux ropes in the PS, resulting in the second CME; the current sheet formed below the second erupted flux rope causes reconnection at the overlying arcades of the other flux rope in the PS, leading to the third CME. The latter two CMEs can happen in a more generic configuration, without a flux rope outside the PS to erupt at first to trigger them, although the underlying evolution is the same (Lynch & Edmondson 2013). The model of Török et al (2011) or Lynch & Edmondson (2013 is applicable in a PS configuration.…”

“…The latter two CMEs can happen in a more generic configuration, without a flux rope outside the PS to erupt at first to trigger them, although the underlying evolution is the same (Lynch & Edmondson 2013). The model of Török et al (2011) or Lynch & Edmondson (2013 is applicable in a PS configuration. More generally, it is applicable in a configuration with a closed flux system containing a flux rope located near the erupting flux rope, e.g., a quadrupolar configuration, such as the D-type CME and its preceding one from AR 10030 shown in Figure 4.…”

“…More generally, it is applicable in a configuration with a closed flux system containing a flux rope located near the erupting flux rope, e.g., a quadrupolar configuration, such as the D-type CME and its preceding one from AR 10030 shown in Figure 4. The CME had a waiting time of 1 hr, following a process similar to the second and third CMEs in Török et al (2011), or the two CMEs in Lynch & Edmondson (2013), according to Gary & Moore (2004): the core flux rope of the first CME was released from one flux tube system in a quadrupolar region by a breakout reconnection at the X point above the region; the neighboring flux rope started to expand and finally erupted out owing to the decrease of the overlying magnetic tension, which was caused by the reconnection at the current sheet formed below the first erupted flux rope.…”