CMG Research: Collaborative Research: Models of Sub-Grid Scale Turbulence in Earth's Core and the Geodynamo

保罗·H.地球的发电机是地磁场的主要来源，它是一个涉及广泛的相互作用尺度、复杂的几何形状和丰富多样的物理过程的地球系统。数值模拟仅解决最大尺度的特征;较小的亚网格尺度过程的大多数参数化仅模拟耗散过程，并且无法模拟影响不同空间尺度之间能量转移的非耗散过程。 最近发展的相似性模型和Navier-Stokes-alpha模型也支持这一观点。核心动力学受到科里奥利力和洛伦兹力的强烈影响，使场具有各向异性和非局部性。 最近的研究为这些过程提供了有价值的见解，这将有助于激发准确解释这些力的广义模型。 该项目将把小规模场结构的知识纳入相似性和纳维尔-斯托克斯-阿尔法模型，从而更好地确定地核次网格过程的参数。该项目将把数值模拟和理论分析结合起来，不仅采用分离物理过程和分析问题的简化模型，而且采用现实的地球发电机模型。这项研究将由来自美国和国外的数学家和地球科学家在一个管理小组的监督下进行。 该项目将促进发电机集体成员之间的互动，预计该项目将组织并部分支持的年度讲习班将产生进一步的合作。 预计改进参数化的次网格过程中旋转磁对流将感兴趣的所有谁愿意研究磁性和发电机在其他行星和恒星。 据信，其中许多人将希望参加计划中的讲习班。地球发电机的改进数值模型将引起第二组地球科学家和数学家的兴趣，他们试图量化我们星球内部的结构，动力学和历史。

EAR-0222334Paul H. Roberts Earth's dynamo, which is responsible for the geomagnetic field, is a geosystem involving a broad range of interacting scales, a complex geometry and a rich variety of physical processes. Numerical simulations resolve only the largest-scale features; most parameterizations of the smaller, subgrid scale processes simulate dissipative processes only, and are incapable of simulating non-dissipative processes which affect transfers of energy among differing spatial scales. Exceptions to this statement are the recently developed similarity and Navier-Stokes-alpha models. Core dynamics is strongly affected by the action of the Coriolis and Lorentz forces, making the fields both anisotropic and non-local. Recent studies have provided valuable insight into these processes, which will help motivate generalized models that accurately account for these forces. This project will develop better parameterizations of subgrid processes in Earth's core by incorporating into the similarity and Navier-Stokes-alpha models, knowledge of the structure of the small-scale fields. The project will involve a combination of numerical simulation and theoretical analysis employing not only simplified models that isolate physical processes and analytical issues, but also realistic geodynamo models. The research will be undertaken by a group of mathematicians and geoscientists from US institutions and from abroad under the supervision of a management group. The project will foster interactions between members of the dynamo collective, and it is expected that further collaborations will result from the annual workshops that will be organized and partially supported by the project. It is anticipated that improved parameterization of subgrid processes in rotating magnetoconvection will interest all who wish to study magnetism and dynamos in other planets and in stars. It is believed that many of these people will wish to participate in the planned workshops. An improved numerical model of the geodynamo will be of interest to a second group of geoscientists and mathematicians who seek to quantify the structure, dynamics and history of the interior of our planet.--