Solar eruptions are spectacular magnetic explosions in the Sun’s corona, and how they are initiated remains unclear. Prevailing theories often rely on special magnetic topologies that may not generally exist in the pre-eruption source region of corona. Here, using fully three-dimensional magnetohydrodynamic simulations with high accuracy, we show that solar eruptions can be initiated in a single bipolar configuration with no additional special topology. Through photospheric shearing motion alone, an electric current sheet forms in the highly sheared core field of the magnetic arcade during its quasi-static evolution. Once magnetic reconnection sets in, the whole arcade is expelled impulsively, forming a fast-expanding twisted flux rope with a highly turbulent reconnecting region underneath. The simplicity and efficacy of this scenario argue strongly for its fundamental importance in the initiation of solar eruptions.

太阳爆发是太阳日冕中壮观的磁爆炸，它们是如何引发的仍不清楚。流行的理论通常依赖于在日冕的喷发前源区域中通常不存在的特殊磁拓扑。在这里，使用高精度的全三维磁流体动力学模拟，我们表明太阳爆发可以在单个双极配置中启动，而无需额外的特殊拓扑。仅通过光球剪切运动，在其准静态演化过程中，在磁拱廊的高剪切核心场中形成电流片。一旦磁重联开始，整个拱廊就会被冲动地排出，形成一个快速膨胀的扭曲磁通绳，下方有一个高度湍流的重联区域。