Alternative driving mechanisms for the geodynamo: Precession and double diffusive convection

地球发电机的替代驱动机制：进动和双扩散对流

• 批准号: 5428672
• 负责人: Professor Dr. Andreas Tilgner
• 金额: --
• 依托单位: Institut für Astrophysik und Geophysik
• 依托单位国家: 德国
• 项目类别: Priority Programmes
• 财政年份: 2004
• 资助国家: 德国
• 起止时间: 2003-12-31 至 2008-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/5428672?language=en
• 关键词: Alternative; driving; mechanisms; geodynamo; Precession

A large number of simulations of the geodynamo exist in which the flow in the Earth's core is assumed to be driven by convection alone. However, it is possible that precession is actually driving the geodynamo by drawing on the rotational energy stored in the Earth-Moon system. A precession driven dynamo implies potentially observable effects on the motion of the Earth and the Moon. If indeed the geodynamo is convectively driven, the magnetic field is likely to be maintained by compositional convection with some admixture of thermal convection, so that we are dealing with double diffusive convection. The present proposal intends to elucidate whether a precession driven dynamo is accessible numerically, whether there are observable consequences of precession driving the dynamo, and whether there are qualitatively new effects introduced by double diffusion should the geodynamo be driven by compositional convection.

存在大量关于地球发电机的模拟，其中假定地核中的流动仅由对流驱动。然而，有可能进动实际上是通过利用储存在地月系统中的旋转能量来驱动地球发电机的。进动驱动的发电机意味着对地球和月球运动的潜在可观察到的影响。如果地球发电机确实是对流驱动的，磁场很可能通过成分对流和一些热对流的混合物来维持，所以我们处理的是双扩散对流。本提案旨在阐明进动驱动发电机是否在数值上是可行的，进动驱动发电机是否有可观察到的后果，以及如果地球发电机是由成分对流驱动的，是否存在双重扩散带来的质的新效应。