SGER: Coronal Mass Ejection (CME) Initiations as a Result of Magnetic Helicity Accumulation in the Corona

PI提议进行为期一年的调查，以研究和测试她与co -PI Low在之前的NSF SHINE（美国国家科学基金会太阳，日光层和行星际环境）奖的支持下开发的理论。Zhang-Low理论认为日冕物质抛射（cme）是日冕演化的自然最终产物，是日冕中磁螺旋度积累的结果。这一理论将在理论上和观测上进行研究和检验。提出者将首先研究一个MHD（磁流体力学）猜想，即存在一个无力场所能包含的总磁螺旋度的上界。如果存在这样一个上限，那么超过这个上限的磁螺旋度的积累自然会导致日冕物质抛射的爆发。提议者还将使用矢量磁场测量来研究几个活跃区域的磁螺旋度演变，以检验观测结果是否与日冕物质抛射发生在磁螺旋度显著积累时期的理论相一致。拟议的工作在智力上具有挑战性和创新性，因为它将改变科学家看待日冕动力学的方式，并将需要制定日冕物质抛射引发预测的新方法。拟议工作的结果将对太阳能和空间界产生广泛的影响。这项工作将有助于了解基本的CME物理，并为空间天气预报提供一个有前途的基于物理的工具。

The PI proposes a one-year investigation to study and test a theory she developed with Co-PIs Low with support from a previous NSF SHINE (National Science Foundation Solar, Heliospheric, and INterplanetary Environment) award. The Zhang-Low theory states that coronal mass ejections (CMEs) are a natural end product of coronal evolution because of the accumulation of magnetic helicity in the corona. This theory will be investigated and tested both theoretically and observationally in this effort. The proposers will first investigate an MHD (magnetohydrodynamic) conjecture that there is an upper bound on the total magnetic helicity that a force-free field can contain. If such an upper bound exists, the accumulation of magnetic helicity in excess of this limit will naturally result in an eruption of a CME. The proposers will also use vector magnetic field measurements to study the magnetic helicity evolution in several active regions to test whether observations do show consistence with the theory that CMEs are occurring at times of significant accumulation of magnetic helicity. The proposed work is intellectually challenging and innovative, because it will change the way scientists view coronal dynamics and will require formulations of new approaches to CME-initiation prediction.The results of the proposed work will have a broad impact on solar and space community. This effort will contribute to the understanding of fundamental CME physics as well as provide a promising physics-based tool for space weather prediction.