Flows and Magnetic Fields in Complex Sunspots and their Role in Producing Solar Flares

日冕物质抛射和耀斑是太阳上最突出的能量事件，甚至可以影响地球和近地环境。在当今技术驱动的社会中，准确了解此类爆发事件的可能性以及预测其发生的有效方法对于保护空间和地面资产至关重要。然而，关于耀斑的性质和触发它们的机制，许多基本问题仍然悬而未决。最近，在太阳耀斑之后，观测到了光球磁场的快速变化，整个太阳黑子半影永久地消失了。沿着磁中性线的剪切流是复杂太阳黑子中特殊流动的一个例子，它可能有助于磁场剪切积聚并导致非位势磁场。具有高空间、时间和光谱分辨率的二维光谱和偏振测量为研究这些现象和推进我们对太阳黑子复杂和高动态性质的理解提供了一个极好的机会。这项研究项目是格雷戈尔太阳望远镜的关键科学项目之一，该望远镜将于2011年夏天在西班牙特内里费岛的泰德天文台投入使用。格雷戈尔-法布里-佩罗涉仪将在2011-14年格雷戈尔科学演示期间使用，以放大与太阳耀斑有关的小范围过程，而来自地面和(新的)空间飞行任务的更多数据将提供必要的背景。

Coronal mass ejections (CMEs) and flares are the most prominent energetic events on the Sun, which can even affect the Earth and the near-Earth environment. In today’s technology-driven society, precise knowledge about the likelihood of such eruptive events and effective ways of forecasting their occurrence are essential to protect assets both in space and on the ground. However, many fundamental questions remain open about the nature of flares and the mechanisms that trigger them. Recently, rapid changes of photospheric magnetic fields have been observed after solar flares, where entire segments of sunspot penumbrae permanently vanished. Shear flows along the magnetic neutral line are an example of peculiar flows in complex sunspots, which might contribute to magnetic shear buildup and lead to non-potential magnetic fields. Two-dimensional spectroscopy and polarimetry with high spatial, temporal, and spectral resolution provides an excellent opportunity to study these phenomena and to advance our understanding of the complex and highly dynamic nature of sunspots. This research project is one of the key science projects for the GREGOR solar telescope, which will become operational at Observatorio del Teide, Tenerife, Spain in the summer of 2011. The GREGOR Fabry-Pérot Interferometer (GFPI) will be used during the GREGOR science demonstration in 2011–14 to zoom in on the small-scale processes associated with solar flares, while additional data from ground-based and (new) space missions will provide the necessary context.