地球外核中的磁旋MRI
Magnetostrophic MRI in the Earth's Outer Core
摘要：
我们表明，一个简单的，修改后的版本的磁旋转不稳定性（MRI）可以开发在地球的外液核，在存在的背景剪切。它需要热成风，或一个主要的不稳定性，如对流，以驱动核心内的弱差异旋转。地核中的力平衡与MRI的经典天体物理学应用（如恒星周围的气体盘）非常不同。在这里，地球核心的弱差异旋转通过与行星更大的旋转速率的建设性相互作用产生不稳定性。由此产生的不稳定机制刚好足以抵消稳定电阻效应，并在有趣的时间尺度上产生增长。我们给出了一个简单的物理解释的不稳定性，并表明，它依赖于一个力的平衡适当的地球的核心，称为磁旋平衡。
英文摘要：
We show that a simple, modified version of the Magnetorotational Instability (MRI) can develop in the outer liquid core of the Earth, in the presence of a background shear. It requires either thermal wind, or a primary instability, such as convection, to drive a weak differential rotation within the core. The force balance in the Earth's core is very unlike classical astrophysical applications of the MRI (such as gaseous disks around stars). Here, the weak differential rotation in the Earth core yields an instability by its constructive interaction with the planet's much larger rotation rate. The resulting destabilising mechanism is just strong enough to counteract stabilizing resistive effects, and produce growth on geophysically interesting timescales. We give a simple physical explanation of the instability, and show that it relies on a force balance appropriate to the Earth's core, known as magnetostrophic balance.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
