Analysis of Flows Inside Quiescent Prominences as Captured by Hinode/Solar Optical Telescope

TL;DR

This study analyzes plasma flows within quiescent solar prominences using Hinode data, revealing energy spectra, vorticity, anisotropy, and oscillations to better understand magnetic stability and eruption potential.

Contribution

It presents the first analysis of two-dimensional kinetic energy and enstrophy spectra in prominences, utilizing velocity maps derived from Hinode observations.

Findings

Kinetic energy PSD indices range from -1.00 to -1.60.

All prominences show an inertial range of $0.8 \, \leq \, k \leq 2.0$ rad/Mm.

Detected quasi-periodic oscillations in velocity centroid for one prominence.

Abstract

Developing an understanding of how magnetic fields can become entangled in a prominence is important for predicting a possible eruption. This work investigates the kinetic energy and vorticity associated with plasma motion residing inside quiescent prominences (QPs). These plasma flow characteristics can be utilized to improve our understanding of how the prominence maintains a stable magnetic field configuration. Three different contrast-enhanced solar prominence observations from Hinode/Solar Optical Telescope were used to construct velocity maps -- in the plane of the sky -- via a Fourier local correlation tracking program. The resulting velocities were then used to perform the first ever analysis of the two-dimensional kinetic energy and enstrophy spectra of a prominence. Enstrophy is introduced here as a means of quantifying the vorticity that has been observed in many QPs. The kinetic energy power spectral density (PSD) produced indices ranging from -1.00 to -1.60. There was a consistent anisotropy in the kinetic energy spectrum of all three prominences examined. Examination of the intensity PSD reveals that a different scaling relationship exists between the observed prominence structure and velocity maps. All of the prominences exhibited an inertial range of at least $0.8 \leq k\leq 2.0\; \textrm{rads} \: \textrm{Mm}^{-1}$. Quasi-periodic oscillations were also detected in the centroid of the velocity distributions for one prominence. Additionally, a lower limit was placed on the kinetic energy density ($\epsilon \, \sim 0.22-7.04\: \mathrm{km}^{2}\textrm{s}^{-2}$) and enstrophy density ($\omega \, \sim 1.43-13.69\: \times 10^{-16} \, \textrm{s}^{-2}$) associated with each prominence.