A numerical experiment relevant to line-tied reconnection in two-ribbon flares
✍ Scribed by T. G. Forbes; E. R. Priest
- Publisher
- Springer
- Year
- 1983
- Tongue
- English
- Weight
- 953 KB
- Volume
- 84
- Category
- Article
- ISSN
- 0038-0938
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✦ Synopsis
The nonlinear evolution of a reconnecting magnetic field configuration similar to that occurring just before the onset of'post'-flare loops in two-ribbon flares is determined. The evolution, which is obtained by numerically solving the resistive MHD equations, shows two new features that have not yet been incorporated into contemporary models of'post'-flare loops. The first of these new features is the formation of a nearly stationary fast-mode shock above the region corresponding to the top of the loops. This fast-mode shock occurs just below the magnetic neutral line and between the slow-mode shocks associated with fast magnetic reconnection at the neutral line. The second new feature is the creation and annihilation of large-scale magnetic islands in the current sheet above the loops. The annihilation of the islands occurs very rapidly and appears to be a manifestation of the coalescence instability. The creation and annihilation of magnetic islands could be important in understanding the energetics of 'post'-flare loops since the coalescence instability can produce an intermittent energy release more than an order of magnitude faster than that predicted by steady-state reconnection theories.