Counter‐Helical Magnetic Flux Ropes From Magnetic Reconnections in Space Plasmas

• Published in: Geophysical research letters 2024-04, Vol.51 (7), p.n/a
• Main Authors: Jia, Ying‐Dong, Qi, Yi, Wang, Xueyi, Miles, Nathan, Russell, C. T., Wei, Hanying
• Format: Article
• Language: English
• Subjects: Aerospace environments; Corona; Electric currents; Evolution; Fluctuations; Heating; Helicity; Magnetic field; Magnetic fields; Magnetic flux; magnetic flux ropes; Magnetic reconnection; Magnetohydrodynamics; magnetospheres; Magnetospheric-solar wind relationships; Planetary magnetospheres; plasma; Ropes; Solar corona; Solar wind; Space plasmas; Space weather
• ISSN: 0094-8276; 1944-8007
• DOI: 10.1029/2024GL108270

Magnetic flux ropes are ubiquitous in various space environments, including the solar corona, interplanetary solar wind, and planetary magnetospheres. When these flux ropes intertwine, magnetic reconnection may occur at the interface, forming disentangled new ropes. Some of these newly formed ropes contain reversed helicity along their axes, diverging from the traditional flux rope model. We introduce new observations and interpretations of these newly formed flux ropes from existing Hall Magnetohydrodynamics model results. We first examine the time‐varying local magnetic field direction at the impact interface to assess the likelihood of reconnection. Then we investigate the electric current system to describe the evolution of these structures, which potentially accelerate particles and heat the plasma. This study offers novel insights into the dynamics of space plasmas and suggests a potential solar wind heating source, calling for further synthetic observations. Plain Language Summary This research examines a special type of systematically twisted magnetic fields, known as flux ropes, in the sun's atmosphere, the solar wind, and near planets. Built on earlier model results, this examination brings a new understanding of how these special flux ropes emerge from collisions between flux ropes. These results use a commonly used simulation tool for large‐scale plasmas to study the new ropes formed after two flux ropes are pushed toward each other long enough. In some cases, each of the new ropes may have opposite twists between their two ends. We then examine how the magnetic field changes across the interface during the evolution. Changes in electric currents found in these situations further explain the formation and evolution of the new rope pairs. This examination helps to better understand the behavior of space plasma's heating of the solar wind and its control of space weather. Key Points We examine the interaction of magnetic flux ropes that consist of opposite helicity along their axes using numerical simulations We present the evolution of their current system, from which we anticipate a significant amount of energy release These structures could be present on the solar surface, in the solar wind, and in magnetospheres