NSF-SNSF: Dynamics of the Earth's core under the plesio-geostrophy paradigm

NSF-SNSF：近地转范式下的地核动力学三维数值模拟是理解地球磁场起源的重要工具。但是，必须谨慎使用这些工具，因为使用现实参数值的计算超出了当前计算能力的范围。相反，该团队建议基于降低复杂性的模型开发一类新的模拟。这些模型被设计成利用实际模型参数的极值进行近似。实际上，它们利用了使三维模拟不切实际的特性。拟议的研究将在各种环境中对简化的复杂性模型进行严格的测试。最终目标是以前所未有的逼真度模拟地球核心的对流和磁场产生。这项工作将为产生地球磁场所需的能量提供见解。该团队还将通过将降低复杂性的模型与先前的观测相结合来预测磁场变化，这一过程称为数据同化。这是一项使用启发的研究，旨在实现对磁场的可靠预测。这使得能够规划空间飞行任务，因为磁场的变化会调节太阳和宇宙辐射对航天器的影响。这项合作是通过美国国家科学基金会和瑞士国家科学基金会牵头机构机遇基金会实现的。该团队的具体研究计划依赖于几个关键要素。首先，他们将扩展一个新的理论公式，降低复杂性模型称为近地转。这个公式明确地解释了非常低的流体粘度和快速的行星旋转的影响。这是传统三维模拟的两个主要障碍。第二，它们将通过处理赤道地区发生的特殊动态来解决所有降低复杂性模型的长期挑战。他们将联合收割机结合这些元素来探索问题的层次结构，以评估PG公式在捕获地核中正确物理学方面的效率。成功地确认PG模式的可靠性将是变分资料同化问题的起点。该项目的成果包括通过提供开放源码软件，使研究人员能够调查核心的短期动态，对研究基础设施作出重大贡献。这也将是努力实施数据同化方法的起点。该团队希望这项工作能够对地核的动力学产生新的见解，并为预测地磁场奠定基础。瑞士项目由美国国家科学基金会（NSF）和瑞士国家科学基金会（SNSF）资助，其中NSF资助美国研究人员，SNSF资助瑞士的合作伙伴。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

NSF-SNSF: Dynamics of the Earth’s core under the plesio-geostrophy paradigmThree-dimensional numerical simulations are an important tool for understanding the origin of the Earth’s magnetic field. However, these tools must be used with caution because calculations with realistic parameter values are beyond the reach of current computational capabilities. Instead, the team proposes to develop a new class of simulations based on reduced complexity models. These models are designed to make approximations that exploit the extreme values of realistic model parameter. In effect, they take advantage of the very properties that make three-dimensional simulations impractical. The proposed research will undertake rigorous tests of the reduced complexity models in a variety of settings. The end goal is to simulate convection and magnetic-field generation in the Earth's core with unprecedented fidelity. This work will provide insights into the power needed to generate the Earth's magnetic field. The team will also gain an ability to forecast changes in the magnetic field by combining the reduced complexity models with prior observations, a process known as data assimilation. This is use-inspired research to enable reliable forecasting of the magnetic field. This enables the planning of space missions because changes in the magnetic field modulate the effect of solar and cosmic radiation on spacecraft . This collaborative effort is made possible through the National Science Foundation and Swiss National Science Foundation Lead Agency Opportunity.The team's specific research plan relies on several key elements. First, they will extend a new theoretical formulation of reduced complexity models called plesio-geostrophy. This formulation explicitly accounts for the influences of very low fluid viscosity and rapid planetary rotation. These are the two main barriers to conventional three-dimensional simulations. Second, they will address a long-standing challenge for all reduced complexity models by dealing with the special dynamics that occurs in the equatorial region. They will combine these elements to explore a hierarchy of problems to assess the efficiency of the PG formulation in capturing the correct physics in Earth's core. Success in confirming the reliability of the PG model will be a starting point for the problem of variational data assimilation. Outcomes of this project include a major contribution to research infrastructure by providing open-source software to enable researchers to investigate short-period dynamics of the core. It would also be the starting point for efforts to implement data assimilation methods. The team expects this work to produce novel insights into the dynamics of the Earth's core and to establish the groundwork for forecasting the geomagnetic field.This collaborative U.S.-Swiss project is supported by the U.S. National Science Foundation (NSF) and the Swiss National Science Foundation (SNSF), where NSF funds the U.S. investigator and SNSF funds the partners in Switzerland.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.