Tracking the Evolution of Plasma Instabilities from the Prominence-Corona Transition Region into Interplanetary Space with Total Solar Eclipse and WISPR/PSP White Light Images

TL;DR

The paper investigates how plasma instabilities rooted in the prominence–corona transition region (PCTR)—specifically vortex rings, Kelvin–Helmholtz (KH) waves, and CMEs—evolve from near the Sun into interplanetary space by combining total solar eclipse (TSE) white-light images with PSP/WISPR observations. Using ellipse fitting for rings, crest spacing for KH waves, and CME envelopes, the authors quantify size–distance relationships and infer speeds, revealing a consistent evolution where these structures persist and accelerate with the solar wind. The key findings include a global consistency between TSE and WISPR morphologies, an acceleration of features beyond ~$3\,R_s$, and inferred near-Sun vortex-ring speeds of $v_1\approx$ a few tens of km s$^{-1}$ that connect to in-situ slow solar-wind speeds via mass-flux considerations, e.g., $v_2$ around $249\pm25$ km s$^{-1}$ for distant rings and $v_1\approx19.4\pm3.2$ km s$^{-1}$ near the Sun. Overall, the study provides strong empirical evidence that PCTR-origin instabilities survive expansion into the heliosphere and likely contribute to corona–solar wind turbulence, highlighting the complementary value of TSEs and WISPR data for tracking solar-plasma dynamics across large radial distances.

Abstract

High-resolution total solar eclipse (TSE) white light (WL) images are the only observations at present to capture coronal structures over an uninterrupted field of view (FoV) of at least 10 solar radii (Rs) starting from the solar limb. They were the first to report the presence of vortex rings originating within the prominence-corona transition region (PCTR). They also captured CMEs and Kelvin-Helmholtz (KH) instabilities at different phases of their evolution. While the evolution of CMEs and KH waves is relatively well-documented, little is known about the survivability of vortex rings beyond the FoV of the TSE images. In this study, we use seven TSE images and non-contemporaneous WL images acquired by the Wide-Field Imager for Parker Solar PRobe (WISPR) to track the spatial evolution of vortex rings, KH waves, and CMEs. The size trend versus radial distance for vortex rings and KH waves are found to be shallower below 1.5 Rs than beyond 3 Rs, while the CMEs observed beyond 3 Rs show a unique slope. The WISPR time series yield an average speed of 249.02 +/- 25.3 km/s for the vortex rings beyond 3 Rs, that when combined with their size yields a speed of 19.39 +/- 3.20 km/s below 1 Rs. These values are remarkably consistent with the acceleration profile of the slow solar wind over the same distance. This study provides strong empirical evidence that vortex rings, which originate at the PCTR with complex magnetic structures, do not dissipate as they expand away from the Sun with the solar wind.

Figures (13)

• Figure 1: Prominence eruption during the flare of 2011 June 7 as captured by SDO/AIA as composite images from the 304, 171, and 211 Å channels in SDO/AIA. This composite was processed using the NAFE algorithm Druckmuller_2013. The white arrows point to the twirling filaments in the prominence. The orange arrows point to the very faint envelope of the ensuing CME. This example shows the complexity of the twirling motion of the prominence as it erupted between the opposite magnetic polarities of the sunspots underlying the active region. The associated animation shows the SDO/AIA composite spanning 2011 July 06 06:03 UT to 06:42 UT with 12 s cadence (8 s total duration).
• Figure 2: The 2019 July 22 TSE white light image at solar minimum, with the four enlarged panels A, B, C, and D, below. Although ubiquitous in all frames, a few vortex rings are encircled in panels A, C, and D as a guide. In panel A, a KH$^*$ at chromospheric (H$\alpha$) temperature and another at coronal temperatures (white) are encircled by ellipses. Another KH is detected in panel B. An intricate connectivity between prominence and coronal material is captured in panel A.
• Figure 3: Top panel: The 2020 December 14 TSE white light image around solar minimum. Details of regions A, B, C, D, and E are shown in more detail below. Panel A highlights the filamentary nature of a huge CME bubble off the east limb, with a KH wave along its flank (ellipse). Panel B shows a sequence of expanding loops above the prominence cavity. Box C is a close-up of turbulence within a prominence cavity. Panels E and D captured the KH waves (ellipses).
• Figure 4: Top panel: The 2021 December 4 TSE white light image at 07:45 UT taken from Union Glacier in Antarctica by Andreas Möller around solar minimum. The details in panel A highlight a huge KH wave instability, most likely triggered by a prominence eruption followed by a CME (see arrow pointing to kink). Panel B shows vortex rings (circles) in the proximity of the CME cavity and close to the PCTR. Panel C shows another example of vortex rings in the proximity of a PCTR and KH wave instabilities.
• Figure 5: The 2012 November 13 TSE white light image at solar maximum, acquired by Constantinos Emmanoulidis. Panel A shows a rising twisted filament with adjoining KH waves (enclosed within ellipses). In panel B, vortices are seen emerging in a prominence cavity. Panel C is an example of KH instabilities similar to those found in Fig. \ref{['tse2021C']}A, albeit with smaller amplitudes.