Core Dynamics and the Geodynamo

罗伯茨EAR-0074015地球磁场是由流动在地球铁芯中的电流产生的。这些电流是由自激发电机动作产生的。如同在发电站中一样，导体在磁场作用下的运动会产生产生磁场本身的电流。地核中流体运动的能量来源通常被认为是地球冷却时在固体内核表面释放的物质的热和成分浮力，成功的地球发电机模拟已经基于这一想法。还有第二种可能的能源，即地球自转轴的月球-太阳进动。这从未被评估为地球磁力的可能来源。这项调查的目的是确定岁差是否能够维持地球发电机，从而创造出一个类似地球的磁场。如果它未能做到这一点，目标将是找出岁差力量如何改变成功的浮力驱动的地球发电机产生的磁场。

Roberts EAR-0074015 The magnetic field of the Earth is created by electric currents flowing in the Earth's molten-iron core. These currents are generated by self-excited dynamo action. As in a power station, the motion of the conductor in the presence of the magnetic field produces the currents that create the magnetic field itself. The energy source for the fluid motions in the Earth's core is commonly supposed to be the thermal and compositional buoyancy of material released at the surface of the solid inner core as the Earth cools, and successful geodynamo simulations have been based on this idea. There is also a second possible energy source, the luni-solar precession of the Earth's axis of rotation. This has never been evaluated as a possible source of the Earth's magnetism. It is the object of this investigation to determine whether precession can maintain a geodynamo that creates an Earth-like field. If it fails to do so, the aim will be to find how precessional forces alter the fields produced by the successful buoyancy-driven geodynamo.