Orientation and Stability of Asymmetric Magnetic Reconnection X Line
- Dartmouth College, Hanover, NH (United States). Dept. of Physics and Astronomy
- Univ. of Bergen (Norway). Dept. of Physics and Technology; Southwest Research Inst. (SwRI), San Antonio, TX (United States)
- NASA Goddard Space Flight Center (GSFC), Greenbelt, MD (United States)
- Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
Here, the orientation and stability of the reconnection x line in asymmetric geometry is studied using three-dimensional (3-D) particle-in-cell simulations. We initiate reconnection at the center of a large simulation domain to minimize the boundary effect. The resulting x line has sufficient freedom to develop along an optimal orientation, and it remains laminar. Companion 2-D simulations indicate that this x line orientation maximizes the reconnection rate. The divergence of the nongyrotropic pressure tensor breaks the frozen-in condition, consistent with its 2-D counterpart. We then design 3-D simulations with one dimension being short to fix the x line orientation but long enough to allow the growth of the fastest growing oblique tearing modes. This numerical experiment suggests that reconnection tends to radiate secondary oblique tearing modes if it is externally (globally) forced to proceed along an orientation not favored by the local physics. Finally, the development of oblique structure easily leads to turbulence inside small periodic systems.
- Research Organization:
- Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Dartmouth College, Hanover, NH (United States); NASA Goddard Space Flight Center (GSFC), Greenbelt, MD (United States); Univ. of Bergen (Norway)
- Sponsoring Organization:
- USDOE; National Aeronautics and Space Administration (NASA); National Science Foundation (NSF); Research Council of Norway
- Grant/Contract Number:
- AC52-06NA25396; NNX16AG75G; ACI1640768; 223252/F50
- OSTI ID:
- 1477670
- Report Number(s):
- LA-UR-18-26828
- Journal Information:
- Journal of Geophysical Research. Space Physics, Vol. 123, Issue 6; ISSN 2169-9380
- Publisher:
- American Geophysical UnionCopyright Statement
- Country of Publication:
- United States
- Language:
- English
Web of Science
Magnetic Reconnection in the Space Sciences: Past, Present, and Future
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journal | January 2020 |
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