arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 0912.1497astro-ph.SR
收藏

光球与日冕的耦合:线性和湍流区

Coupling Photosphere and Corona: Linear and Turbulent Regimes

A. Verdini, R. Grappin, M. Velli

摘要:

Grappin等人[1]在最近的一项工作中表明,低频运动可以沿着磁回路从一个足点传递到另一个足点,从而模仿日冕对光球的摩擦效应,并使线捆绑近似无效。在这里我们依次考虑高频和湍流阻尼对过程的影响。我们使用一个非常简单的大气模型,它允许分析研究层流情况,并使用简单的现象学参数和更复杂的湍流模型研究湍流情况[2]。我们发现,除了当湍流阻尼是这样的,所有的湍流是阻尼循环遍历过程中,耦合仍然发生在遥远的脚点之间,而且光球运动引起的日冕场饱和在有限的值。

英文摘要:

In a recent work Grappin et al. [1] have shown that low- frequency movements can be transmitted from one footpoint to the other along a magnetic loop, thus mimicking a friction effect of the corona on the photosphere, and invalidating the line-tying approximation. We consider here successively the effect of high frequencies and turbulent damping on the process. We use a very simple atmospheric model which allows to study analytically the laminar case, and to study the turbulent case both using simple phenomenological arguments and a more sophisticated turbulence model [2]. We find that, except when turbulent damping is such that all turbulence is damped during loop traversal, coupling still occurs between distant footpoints, and moreover the coronal field induced by photospheric movements saturates at finite values.

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。

↑