EGU21-827, updated on 08 Jan 2024
https://doi.org/10.5194/egusphere-egu21-827
EGU General Assembly 2021
© Author(s) 2024. This work is distributed under
the Creative Commons Attribution 4.0 License.

Micro-scale tearing mode turbulence in the diffusion region during macro-scale evolution of turbulent reconnection

Takuma Nakamura1, Hiroshi Hasegawa2, Tai Phan3, Kevin Genestreti4, Richard Denton5, and Rumi Nakamura6
Takuma Nakamura et al.
  • 1Institute of Physics, University of Graz, Graz, Austria (takuma.tkm.nakamura@gmail.com)
  • 2Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency
  • 3Space Sciences Laboratory, University of California, Berkeley
  • 4Southwest Research Institute
  • 5Department of Physics and Astronomy, Dartmouth College
  • 6Space Research Institute, Austrian Academy of Sciences

Magnetic reconnection is a key fundamental process in collisionless plasmas that explosively converts magnetic energy to plasma kinetic and thermal energies through a change of magnetic field topology in an electron-scale central region called the electron diffusion region. Past simulations and observations demonstrated that this process causes efficient energy conversion through the formation of multiple macro-scale or micro-scale magnetic islands/flux ropes. However, how these different spatiotemporal scale phenomena are coupled is still poorly understood. In this study, to investigate the turbulent evolution of magnetic reconnection, we perform a new large-scale fully kinetic simulation of a thin current sheet considering a power-law spectrum of initial fluctuations in the magnetic field as frequently observed in the Earth’s magnetotail. The simulation demonstrates that during a macro-scale evolution of turbulent reconnection, the merging of macro-scale islands results in reduction of the rate of reconnection as well as the aspect ratio of the electron diffusion region. This allows the repeated, quick formation of new electron-scale islands within the electron diffusion region, leading to an efficient energy cascade between macro- and micro-scales. The simulation also demonstrates that a strong electron acceleration/heating occurs during the micro-scale island evolution within the EDR. These new findings indicate the importance of non-steady features of the EDR to comprehensively understand the energy conversion and cascade processes in collisionless reconnection.

How to cite: Nakamura, T., Hasegawa, H., Phan, T., Genestreti, K., Denton, R., and Nakamura, R.: Micro-scale tearing mode turbulence in the diffusion region during macro-scale evolution of turbulent reconnection, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-827, https://doi.org/10.5194/egusphere-egu21-827, 2021.

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