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arXiv 0812.3589astro-ph
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洛伦兹力驱动的剪切流:日冕物质抛射和耀斑的能量来源

Shear Flows Driven by the Lorentz Force: An Energy Source for Coronal Mass Ejections and Flares

Ward B. Manchester

摘要:

几十年来,在日冕物质抛射和耀斑的数值模型中,剪切流一直被认为是激发磁场爆发的一种方式。虽然在太阳大气中长期观察到这种剪切流,但直到最近,还没有令人信服的物理解释。本文将讨论的发现,这样的剪切流很容易解释为一个响应的洛伦兹力,自然发生的双极磁场出现和扩大在重力分层的大气。它将被证明,剪切运动运输轴向通量,和磁场能量从淹没的部分领域的扩大部分,强烈耦合太阳内部的日冕。这一物理过程解释了活动区的剪切流,以及为什么发现磁场几乎平行于光球极性反转线,在那里形成双折射。最后,由洛伦兹力驱动的剪切流被证明会在磁弧和磁绳中产生平衡的丧失和喷发,为日冕物质抛射和耀斑提供了令人信服的解释。

英文摘要:

Shear flows have been prescribed in numerical models of coronal mass ejections and flares for decades as a way of energizing magnetic fields to erupt. While such shear flows have long been observed in the solar atmosphere, until recently, there was no compelling physical explanation for them. This paper will discuss the discovery that such shear flows are readily explained as a response to the Lorentz force that naturally occurs as bipolar magnetic fields emerge and expand in a gravitationally stratified atmosphere. It will be shown that shearing motions transport axial flux, and magnetic energy from the submerged portion of the field to the expanding portion, strongly coupling the solar interior to the corona. This physical process explains active region shear flows and why the magnetic field is found to be nearly parallel to photospheric polarity inversion lines where prominences form. Finally, shear flows driven by the Lorentz force are shown to produce a loss of equilibrium and eruption in magnetic arcades and flux ropes offering a convincing explanation for CMEs and flares.

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。

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