Three dimensional computer simulations on the spontaneous fast reconnection model

我们提出了自发快速重连模型，并通过精确的三维计算机模拟研究了其基本物理机制。在各种物理情况下已经明确证明，由于重联区的（微观）反常电阻率与全局重联流之间的正反馈，涉及持续慢激波的快速重联机制可以发生剧烈演化，因此自发的快速重联演化被认为是长电流片系统的非线性不稳定性。结果表明，该理论模型直接导致了大规模磁环的形成，并且在环顶部前方有一个快速激波；此外，还会形成大规模等离子体团并向外传播。最近，仿真模型扩展到了三维，并且阐明了自发快速重联模型的详细3D特征。将自发快速重联模型应用于在遥远尾叶观测到的与亚暴爆发相关的所谓移动压缩区（TCR），并从定性和定量两个方面准确地解释了其基本特征。我们还将该模型应用于地下电流楔，这是一个长期存在的问题，并首次证明了磁层电流楔的剧烈演化。此外，将当前的楔形演化应用于二带耀斑，证明可以有针对性地解释太阳耀斑的主要特征。

We have proposed the spontaneous fast reconnection model, and its basic physical mechanism has been studied by precise three-dimensional computer simulations. It has been definitely demonstrated in a variety of physical situations that the fast reconnection mechanism involving standing slow shocks can drastically evolve because of the positive feedback between the(microscopic)anomalous resistivity in the reconnection region and the global reconnection flow, so that the spontaneous fast reconnection evolution is considered to be a nonlinear instability of the long current sheet system. It is shown that a large-scale magnetic loop formation with a fast shock standing just ahead of the loop top directly results from this theoretical model; also, a large-scale plasmoid is formed and propagates outwards. Recently, the simulation models are extended to three dimensions, and the detailed 3D features of the spontaneous fast reconnection model have been clarified. The spontaneous fast reconnection model is applied to the so-called Traveling Compression Regions (TCR) observed in the distant tail lobe in association with substorm onset, and the basic features are exactly explained both qualitatively and quantitatively. We also apply the model to the substrom current wedge, known as a long-standing question, and demonstrate the drastic evolution of the magnetospheric current wedge for the first time. In addition, the current wedge evolution is applied to two-ribbon flares, and it is demonstrated that major features of solar flares can pertinently explained.