Super-elastic collision of large-scale magnetized plasmoids in the heliosphere

Abstract

Abstract. Super-elastic collision is an abnormal collisional process, in which some particular mechanisms cause the kinetic energy of the system increasing. Most studies in this aspect focus on solid-like objects, but they rarely consider gases or liquids, as the collision of the latter is primarily a mixing process. With cross-field diffusion being effectively prohibited, magnetized plasmoids are different from ordinary gases. But it remains unclear how they act during a collision. Here we present the global picture of a unique collision between two coronal mass ejections in the heliosphere, which are the largest magnetized plasmoids erupting from the Sun. Our analysis for the first time reveals that these two magnetized plasmoids collided like solid-like objects with a 73% likelihood of being super-elastic. Their total kinetic energy surprisingly increased by about 6.6% through the collision, which significantly influenced the dynamics of the plasmoids.

Interplanetary and Geomagnetic Consequences of Interacting CMEs of 13 – 14 June 2012

“…These observations have also revealed direct evidence of CME-CME interaction when they are launched in close succession in the same direction Lugaz et al, 2012;Shen et al, 2012;Mishra, Srivastava, and Chakrabarty, 2015). In fact, CME interactions are now commonly observed, in particular, around solar maximum when the occurrence of CMEs is larger in number.…”

“…We made several independent mass measurements for this event and found that the values are within 20% of the measured ones. Further, the role of the uncertainty in the mass estimation has been studied to understand the variation in the coefficient of restitution which has been found to be negligible in deciding the nature of the collision (Shen et al, 2012;Mishra, Wang, and Srivastava, 2016). This is expected as our approach constrains the momentum conservation while modifying the observed post-collision speeds .…”

“…Based on these observations of interacting CMEs, some of the crucial questions have been aptly addressed as to whether the nature of interaction is elastic, inelastic, or super-elastic? (Lugaz et al, 2012;Shen et al, 2012;Mishra, Srivastava, and Chakrabarty, 2015;Mishra, Wang, and Srivastava, 2016). Further, using in situ observations, it may also be possible to answer the question, under what conditions, interacting CMEs lead to a merged or a separate structure.…”

On the Collision Nature of Two Coronal Mass Ejections: A Review

“…This largely stimulated the observational and numerical studies in this area (e.g. Gopalswamy et al, 2009;Xiong, Zheng, and Wang, 2009;Temmer et al, , 2014Shen et al, 2012a;Liu et al, , 2014Martínez-Oliveros et al, 2012;Webb et al, 2013;Shen et al, 2011Shen et al, , 2012bShen et al, , 2013Shen et al, , 2016Mishra and Srivastava, 2014;Mishra, Srivastava, and Chakrabarty, 2015;Mishra, Srivastava, and Singh, 2015;Mishra, Wang, and Srivastava, 2016;Shanmugaraju et al, 2014;Colaninno and Vourlidas, 2015). A comprehensive review about the interaction of successive CMEs and consequences in particle acceleration and geoeffectiveness by Lugaz et al (2017) can be found in the Topical Collection called Earth-affecting Solar Transients.…”

“…The first discussion of the momentum exchange during a CME-CME interaction appeared in , who proposed four interaction scenarios. The first detailed and comprehensive study focusing on the collision nature between two CMEs was presented by Shen et al (2012a), who proposed a superelastic behavior in the collision of CMEs. This promoted a series of subsequent studies.…”