Investigations of the Geodynamo

了解地球磁场的起源并预测其未来的演化是地球科学的关键问题之一。虽然现在几乎普遍认为磁场是由地球外核流体（主要是铁）中的磁流体发电机作用维持的，但对这一过程的细节仍然知之甚少。本项目的具体目标如下：1.研究了最近地球动力学数值模型中磁场产生的基本机制.研究数值发电机模型的参数状态，特别是寻求进一步理解惯性和粘性效应对发电机的作用.研究了热核幔相互作用及其对主磁场形态和长期变化的控制作用.内核引力耦合对地球动力学的影响研究.利用数值发电机模型分析核幔边界磁场图中观测到的特征.冻结通量近似的分析，假设在足够短的时间尺度上，磁场可以被认为是冻结到流体中。7.发电机代码开发，包括开发适合在基于商品硬件的机器网络上运行的分布式存储器版本的代码，以利用这种硬件的性能成本比，这项工作的结果将不仅通过传统的科学出版渠道传播，而且还通过非传统的电视纪录片渠道传播，以确保研究界以外的传播。此外，研究结果将纳入主要研究者的教学材料。

Understanding the origin of the Earth's magnetic field and predicting its future evolution is one of the key problems in the Earth sciences. While it is nowadays almost universally accepted that the magnetic field is maintained by hydromagnetic dynamo action in the Earth's fluid, predominantly iron, outer core, the details of that process remain very poorly understood.This project has the following specific aims:1. Investigation of the basic underlying mechanisms of magnetic field generation in recentnumerical models of the geodynamo.2. Investigation of the parameter regime of numerical dynamo models, seeking in particularto further our understanding of the role of inertial and viscous effects on the dynamo.3. Investigation of thermal core-mantle interactions and their role in controlling the morphology of the main field and its secular variation.4. Investigation of the effect of inner core gravitational coupling on the geodynamo.5. Analysis of features observed in maps of the magnetic field at the core-mantle boundaryusing a numerical dynamo model.6. Analysis of the frozen flux approximation, the assumption under which on sufficiently short timescales the magnetic field can be considered to be frozen into the fluid.7. Dynamo code development, including development of a distributed memory version of the code suitable for running on a network of commodity-hardware based machines in order to take advantage of the performance-cost ratio of such hardware.The results of this work will be disseminated not only through traditional channels of scientific publication but additionally through non-traditional channels television documentaries to ensure dissemination beyond the research community. Additionally, the results will be incorporated into the Principal Investigator's teaching materials.