Three dimensional computer simulations on the spontaneous fast reconnection model

点击翻译按钮获取中文摘要

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.