Three dimensional computer simulations on the spontaneous fast reconnection model

我们提出了自发快速重联模型，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地证明，由于重联区（微观）异常电阻率与整体重联流之间的正反馈，涉及持续缓慢冲击的快速重联机制可以急剧演变，因此自发的快速重联演变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，且磁环顶端有一个快速激波；同时，形成一个大尺度等离子体并向外传播。近年来，将模拟模型扩展到三维，明确了自发快速重联模型的详细三维特征。将自发快速重联模型应用于观测到的与亚暴发生有关的远尾叶行进压缩区（TCR），并从定性和定量上准确地解释了其基本特征。我们还将该模型应用于长期存在的问题亚流楔，并首次证明了磁层电流楔的剧烈演变。此外，将当前的楔形演化应用于双带状耀斑，证明了太阳耀斑的主要特征可以有针对性地解释。

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.