Acquisition of a Computational Facility for Numerical Dynamo Theory

小行星9724568 这项赠款，通过主要研究仪器（MRI）计划，提供178，885美元的部分支持的成本收购一个新的计算设施在哈佛大学建模地球的发电机使用他们最近开发的三维，动态自洽geodynamo代码。 具体来说，他们将购买一台新的Silicon Graphics Origin 2000服务器，配备16个CPU、45 Gb磁盘存储和2 Gb扩展内存。目前Kuang和Bloxham（哈佛）的三维地球发电机模型和Glatzmaier（LANL）和Roberts（UCLA）的模型是世界上目前仅有的两个开发和功能性的地球发电机模型，其结果最近登上了国际和多学科期刊Nature和Science的封面。Kuang-Bloxham模型模拟的磁场产生于内核上方靠近核幔边界的地方，而Glatzmaier-Roberts模型预测的磁场产生于内核上方。 这两个模型都显示了几个衰减时间后的偶极反转，而格拉茨迈尔-罗伯茨模型，这是第一个开发的，已经运行了足够长的时间来模拟其他地磁反转在约。 100，000 ybp和200，000 ybp，得到了地球古地磁反转记录的支持。 这些模型之间的区别在于边界条件的设置和初始参数的选择，每个模型和地球物理基础的每个模型表示可以是，争论。 由于这项研究的计算资源有限，这两个小组被迫对模型进行简化，从而产生可以在合理的时间内运行的代码（Kuang-Bloxham模型目前需要在他们的卡里计算机上花费一个月的专用时间来模拟地球发电机的一个衰减时间）。 考虑到这些限制，使用了不切实际的初始参数值（即Ekman数、Prandtl数、Rayleigh数;参见梅里尔的综述）。 然而，很明显，需要增加并行处理和内存来在合理的时间长度内运行此代码，以在地质上重要的时间段内模拟地球的地球发电机，并且重要的是要支持使用这两种竞争模型的持续开发和后续模拟。 ***

9724568 Bloxham This grant, made through the Major Research Instrumentation (MRI) Program, provides $178,885 as partial support of the costs of acquiring a new computational facility at Harvard University for modeling the Earth's dynamo using their recently developed 3-d, dynamically self-consistent geodynamo code. Specifically, they will acquire a new Silicon Graphics Origin 2000 server with sixteen CPU's, 45 Gb of disk storage and 2 Gb of expanded memory. The current Kuang and Bloxham (Harvard) 3-d geodynamo model and the Glatzmaier (LANL) and Roberts (UCLA) model, whose results have recently been featured on the covers of the international and multi-disciplinary journals Nature and Science, are the only two currently developed and functional models of the geodynamo in the world. The Kuang-Bloxham model simulates a magnetic field that is generated well above the inner core close to the core-mantle boundary, while the Glatzmaier-Roberts model predicts a field generated just above the inner core. Both models show dipole reversals after a few decay times and the Glatzmaier- Roberts model, which was developed first and has been run long enough to simulate other geomagnetic reversals at ca. 100,000 ybp and 200,000 ybp, is supported by the Earth's paleomagnetic reversal records. The difference between these models lies in the setup of boundary conditions and choice of initial parameters for each of the models and the geophysical basis for each model representation can be and is, argued. Given limited computational resources for this research, both groups are forced to make simplifications to the models that result in codes that can be run in a reasonable amount of time (the Kuang-Bloxham model currently requires one month of dedicated time on their CARY computer for simulation of the Earth's dynamo for only one decay time). Given these limitations, unrealistic values of initial parameters are used (i.e. Ekman number, Prandtl number, Rayleigh number; see rev iew by Merrill). However, it is clear that increased parallel processing and memory are required to run this code within reasonable lengths of time to model the Earth's geodynamo over geologically significant time periods and it is important to support continued development and subsequent simulations using both of these competing models. ***