ICS-13 Abstract View


Quasi-Separatrix Layers Induced by Ballooning Instability in Earth's Magnetotail
Zhu, P., pzhu@ustc.edu.cn (1,2)
Wang, Z.-C., wzc1995@mail.ustc.edu.cn (1)
Previous MHD simulations have revealed the dynamically three-dimensional (3D) nature of the magnetic reconnection process induced by ballooning instability in Earth's magnetotail [1,2]. Represented by a generalized Harris sheet, the magnetotail configuration itself is two dimensional due to the symmetry in the dusk-dawn direction. Under certain conditions, such a configuration can become unstable to ballooning instabilities, which in its nonlinear stage can induce the formation of plasmoids, even though there is no pre-existing X-line in the near-Earth magnetotail region. Based on those simulation results, the spatial distribution and structure of the quasi-separatrix layers induced by ballooning instability in Earth's Magnetotail, as well as their temporal evolution, are examined in this work, which indicate that the associated magnetic reconnection can only occur in 3D geometry and is thus irreducible to that of any two-dimensional reconnection process [3]. Such a finding may provide a new perspective to the long-standing controversy over the substorm onset problem, in particular on the potential roles of reconnection and ballooning instabilities. It may also connect to the universal presence of 3D reconnection processes previously discovered in various natural and laboratory plasmas.

[1] P. Zhu and J. Raeder, Phys. Rev. Lett. 110, 235005
[2] P. Zhu and J. Raeder, J. Geophys. Res. Space Physics
119, 131-141 (2014).
[3] P. Zhu, A. Bhattacharjee, A. Sangari, Z.-C. Wang, and
P. Bonofiglo, Phys. Plasmas 24, 024503 (2017).
(1) University of Science and Technology of China, Hefei, Anhui 230026, China
(2) University of Wisconsin-Madison, Madison, WI 53706, USA