Investigations of the Geodynamo

了解地磁场的起源并预测其未来演变是地球科学的关键问题之一。虽然现在人们几乎普遍认为，磁场是由地球流体（主要是铁）外核中的磁发电机作用维持的，但对这一过程的细节仍然知之甚少。本项目有以下具体目标：1。最近地球动力学数值模型中磁场产生的基本机制研究。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。热核-地幔相互作用及其在控制主场形态及其长期变化中的作用的研究。核心区引力耦合对地球动力学影响的研究。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，在此假设下，在足够短的时间尺度上，磁场可以被认为冻结在流体中。Dynamo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代码的分布式内存版本，以便利用此类硬件的性能成本比。这项工作的结果不仅将通过传统的科学出版物渠道传播，而且还将通过非传统的电视纪录片渠道传播，以确保在研究界之外传播。此外，研究结果将被纳入首席研究员的教学材料。

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.