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The evolution of buoyant magnetic structures in the solar interior

太阳内部浮力磁结构的演化

基本信息

批准号：
1908010
负责人：
Nicholas Brummell
金额：
$ 40.33万
依托单位：
University of California-Santa Cruz
依托单位国家：
美国
项目类别：
Standard Grant
财政年份：
2019
资助国家：
美国
起止时间：
2019-09-01 至 2023-08-31
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=1908010&HistoricalAwards=false
关键词：
evolution buoyant magnetic structures solar

项目摘要

One of the great challenges in solar physics is to understand how solar magnetic flux floats from the Sun?s deep interior (where it is generated by the solar dynamo) to the surface. Until now, solar physicists have assumed that magnetic flux could be modeled as discrete magnetically buoyant ?flux tubes.? Recent research has suggested that this idealization might be invalid. The work proposed here will expand that work, and rethink current 3D simulations by modeling solar magnetic flux as concentrations of magnetic field embedded in a diffuse background field. If successful, the work will lead to a fundamental shift in our understanding of the evolution and dynamics of the solar magnetic field, and provide insight into the solar dynamo. The results of this work will provide a theoretical basis for DKIST observations of emerging solar magnetic flux, which is one of the principal goals of the new observatory. This work will also form the basis of a PhD thesis.The proposed work will be to develop a new model for the transport of magnetic flux from deep in the solar interior to the surface through the mechanism of magnetic buoyancy. In particular, the team will replace the idealization of discrete magnetic ?flux tubes? with more physical concentrations of magnetic field set in a diffuse background field. Field lines interweave between the magnetic concentration and the background field, resulting in very different dynamics from what one would expect with discrete flux tubes. This can include mass loss from the rising magnetic concentration, which is prohibited in the flux tube case. They will also increase the fidelity of the simulation by including turbulence in the region through which the magnetic concentration rises. The team will expand prior 2.5D studies into full 3D simulations. This will require the use of supercomputing facilities which were acquired under prior NSF support.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

太阳物理学的巨大挑战之一是了解太阳磁通量如何从太阳深处（由太阳发电机产生）漂浮到表面。到目前为止，太阳物理学家一直假设磁通量可以建模为离散的磁浮力“通量管”。最近的研究表明这种理想化可能是无效的。这里提出的工作将扩展该工作，并通过将太阳磁通量建模为嵌入扩散背景场中的磁场集中来重新思考当前的 3D 模拟。如果成功，这项工作将导致我们对太阳磁场演化和动力学的理解发生根本性转变，并提供对太阳发电机的深入了解。这项工作的结果将为 DKIST 对新兴太阳磁通量的观测提供理论基础，这是新天文台的主要目标之一。这项工作也将构成博士论文的基础。拟议的工作将开发一种新模型，通过磁浮力机制将磁通量从太阳内部深处传输到表面。特别是，该团队将取代离散磁通管的理想化？在扩散背景场中设置更多物理集中的磁场。磁力线在磁集中和背景场之间交织，导致与离散磁通管所期望的动力学截然不同。这可能包括由于磁集中增加而造成的质量损失，这在磁通管情况下是被禁止的。他们还将通过在磁集中上升的区域中加入湍流来提高模拟的保真度。该团队将把之前的 2.5D 研究扩展到完整的 3D 模拟。这将需要使用在之前 NSF 支持下获得的超级计算设施。该奖项反映了 NSF 的法定使命，并通过使用基金会的智力价值和更广泛的影响审查标准进行评估，被认为值得支持。