论文标题
太阳风中的原位换回形成
In-situ switchback formation in the expanding solar wind
论文作者
论文摘要
帕克太阳能探测器最近的近阳性太阳能观察结果发现了一个高度动态的磁性环境，渗透到径向径向场逆转或“换回”。我们表明，观察到的湍流的许多特征是由径向扩展的流动所推动的一系列alfvénic波动复制的。从低振幅向外传播波的简单叠加开始，我们扩展的可压缩式MHD模拟自然会产生折返，因为（i）波的归一化幅度增长，并且由于膨胀而变化，并且（ii）（ii）朝球体偏光（即几乎恒定的磁场强度）演变而来。这些结果表明，在膨胀的太阳风中形成了折返，并不能指示染色体或电晕的冲动过程。
Recent near-sun solar-wind observations from Parker Solar Probe have found a highly dynamic magnetic environment, permeated by abrupt radial-field reversals, or "switchbacks." We show that many features of the observed turbulence are reproduced by a spectrum of Alfvénic fluctuations advected by a radially expanding flow. Starting from simple superpositions of low-amplitude outward-propagating waves, our expanding-box compressible MHD simulations naturally develop switchbacks because (i) the normalized amplitude of waves grows due to expansion and (ii) fluctuations evolve towards spherical polarization (i.e., nearly constant field strength). These results suggest that switchbacks form in-situ in the expanding solar wind and are not indicative of impulsive processes in the chromosphere or corona.
