Tearing Instability and Periodic Density Perturbations in the Slow Solar Wind

Author
Keywords
Abstract
<p>In contrast with the fast solar wind, which originates in coronal holes, the source of the slow solar wind is still debated. Often intermittent and enriched with low first ionization potential elements\textemdashakin to what is observed in closed coronal loops\textemdashthe slow wind could form in bursty events nearby helmet streamers. Slow winds also exhibit density perturbations that have been shown to be periodic and could be associated with flux ropes ejected from the tip of helmet streamers, as shown recently by the WISPR white-light imager on board Parker Solar Probe (PSP). In this work, we propose that the main mechanism controlling the release of flux ropes is a flow-modified tearing mode at the heliospheric current sheet (HCS). We use magnetohydrodynamic simulations of the solar wind and corona to reproduce realistic configurations and outflows surrounding the HCS. We find that this process is able to explain long (\~10-20 hr) and short (\~1-2 hr) timescales of density structures observed in the slow solar wind. This study also sheds new light on the structure, topology, and composition of the slow solar wind, and could be, in the near future, compared with white light and in situ PSP observations.</p>
Year of Publication
2020
Journal
The Astrophysical Journal
Volume
895
Number
Number of Pages
L20
Date Published
05/2020
URL
https://iopscience.iop.org/article/10.3847/2041-8213/ab911d
DOI
10.3847/2041-8213/ab911d