How Does Magnetic Reconnection Drive the Early-stage Evolution of Coronal Mass Ejections?

Abstract

Theoretically, CME kinematics are related to magnetic reconnection processes in the solar corona. However, the current quantitative understanding of this relationship is based on the analysis of only a handful of events. Here we report a statistical study of 60 CME-flare events from August 2010 to December 2013. We investigate kinematic properties of CMEs and magnetic reconnection in the low corona during the early phase of the eruptions, by combining limb observations from STEREO with simultaneous on-disk views from SDO. For a subset of 42 events with reconnection rate evaluated by the magnetic fluxes swept by the flare ribbons on the solar disk observed from SDO, we find a strong correlation between the peak CME acceleration and the peak reconnection rate. Also, the maximum velocities of relatively fast CMEs ( 600 km s −1 ) are positively correlated with the reconnection flux, but no such correlation is found for slow CMEs. A time-lagged correlation analysis suggests that the distribution of the time lag of CME acceleration relative to reconnection rate exhibits three peaks, approximately 10 minutes apart, and on average, acceleration-lead events have smaller reconnection rates. We further compare the CME total mechanical energy with the estimated energy in the current sheet. The comparison suggests that, for small-flare events, reconnection in the current sheet alone is insufficient to fuel CMEs. Results from this study suggest that flare reconnection may dominate

Formation of Magnetic Flux Rope During Solar Eruption. I. Evolution of Toroidal Flux and Reconnection Flux

“…The reconnection rate, i.e., the increasing rate of the reconnected flux, shows an evolution pattern (i.e., fast increase and then slow decrease) like the changing rate of the kinetic and magnetic energies (see also Figure 1), and all of them reach the peak at the same time. Such temporal correlation between reconnection rate (or flare emission) and CME acceleration has been well revealed in observation studies [57,58], stressing the central role and fundamental importance of magnetic reconnection in producing flare and CME [59].…”

Solar Cycle Dependence of ICME Composition

“…CMEs result from eruptions of magnetic flux ropes that can form prior to (Patsourakos, Vourlidas, and Stenborg, 2013;Cheng et al, 2014) and during (Song et al, 2014;Ouyang, Yang, and Chen, 2015) solar eruptions. Studies demonstrate that both magnetic reconnection (Lin and Forbes, 2000;Zhang et al, 2001;Qiu et al, 2004;Maričić et al, 2007;Miklenic, Veronig, and Vršnak, 2009;Zhu et al, 2020) and ideal magnetohydrodynamic instability of flux ropes (Forbes and Priest, 1995;Chen, Hu, and Sun, 2007;Song et al, 2013Song et al, , 2015aSong et al, , 2018 can contribute to the CME acceleration.…”

On the Quasi‐Three Dimensional Configuration of Magnetic Clouds

“…Efforts have been made to relate the MC flux rope configuration with the solar source region properties. Specifically, we have carried out several investigations of comparing magnetic flux contents and field‐line twist profiles in MCs with those derived from flare observations, through in situ modeling of MCs and the analysis of the magnetic reconnection sequences as manifested by the flare‐ribbon brightenings in the source regions (Hu et al., 2014; Qiu et al., 2007; W. Wang et al., 2017, 2019; Zhu et al., 2020). These are largely based on highly quantitative observational analysis, with the understanding that magnetic reconnection (flare process) leads to the formation of the MC flux rope.…”

“…Wang et al, 2017W. Wang et al, , 2019Zhu et al, 2020). These are largely based on highly quantitative observational analysis, with the understanding that magnetic reconnection (flare process) leads to the formation of the MC flux rope.…”