Investigating prominence turbulence with Hinode SOT Dopplergrams

Abstract

Quiescent prominences host a diverse range of flows, including Rayleigh-Taylor instability driven upflows and impulsive downflows, and so it is no surprise that turbulent motions also exist. As prominences are believed to have a mean horizontal guide field, investigating any turbulence they host could shed light on the nature of MHD turbulence in a wide range of astrophysical systems. In this paper we have investigated the nature of the turbulent prominence motions using structure function analysis on the velocity increments estimated from H$\alpha$ Dopplergrams constructed with observational data from Hinode SOT. The pdf of the velocity increments shows that as we look at increasingly small spatial separations the distribution displays greater departure from a reference Gaussian distribution, hinting at intermittency in the velocity field. Analysis of the even order structure functions for both the horizontal and vertical separations showed the existence of two distinct regions displaying different exponents of the power law with the break in the power law at approximately 2000km. We hypothesise this to be a result of internal turbulence excited in the prominence by the dynamic flows of the system found at this spatial scale. We found that the scaling exponents of the p-th order structure functions for these two regions generally followed the p/2 (smaller scales) and p/4 (larger scales) laws that are the same as those predicted for weak MHD turbulence and Kraichnan-Iroshnikov turbulence respectively. However, the existence of the p/4 scaling at larger scales than the p/2 scaling is inconsistent with the increasing nonlinearity expected in MHD turbulence. Estimating the heating from the turbulent energy dissipation showed that this turbulent heating would be very inefficient, but that the mass diffusion through turbulence driven reconnection was of the order of $10^{10}$cm${}^2$/s.

arXiv comment16 pages, 15 figures, accepted for publication in A&A

References in corpus (17)

• The Solar Optical Telescope for the Hinode Mission: An Overview
• Time-Distance Seismology of the Solar Corona with CoMP
• On the Spectrum of Magnetohydrodynamic Turbulence
• On spectral scaling laws for incompressible anisotropic MHD turbulence
• Velocity vectors of a quiescent prominence observed by Hinode/SOT and the MSDP (Meudon)
• Magnetization of cloud cores and envelopes and other observational consequences of reconnection diffusion
• The discovery of geomagnetically trapped cosmic ray antiprotons
• Temporal power spectra of the horizontal velocity of the solar photosphere
• A statistical study of transverse oscillations in a quiescent prominence
• Propagating Waves Transverse to the Magnetic Field in a Solar Prominence
• Numerical Simulations of the Magnetic Rayleigh-Taylor Instability in the Kippenhahn-Schlüter Prominence Model
• Intermittency Spectra of the Magnetic Field in Solar Active Regions
• Relation of Astrophysical Turbulence and Magnetic Reconnection
• Turbulent characteristics in the intensity fluctuations of a solar quiescent prominence observed by the \textit{Hinode} Solar Optical Telescope
• Analysis of Flows Inside Quiescent Prominences as Captured by Hinode/Solar Optical Telescope
• Time evolution of plasma parameters during the rise of a prominence instability
• A statistical study of SUMER spectral images: events, turbulence, and intermittency

Cited by in corpus (9)

• Quiescent prominence dynamics observed with the Hinode Solar Optical Telescope . II. Prominence Bubble Boundary Layer Characteristics and the Onset of a Coupled Kelvin-Helmholtz Rayleigh-Taylor Instability
• Observations of the Kelvin-Helmholtz instability driven by dynamic motions in a solar prominence
• Two-fluid simulations of Rayleigh-Taylor instability in a magnetized solar prominence thread. I. Effects of prominence magnetization and mass loading
• Differences between Doppler velocities of ions and neutral atoms in a solar prominence
• Coronal cooling as a result of mixing by the nonlinear Kelvin--Helmholtz instability
• Impact of Dynamic State on the Mass Condensation Rate of Solar Prominences
• Magnetic field amplification and structure formation by the Rayleigh-Taylor instability
• Simulating Rayleigh-Taylor induced magnetohydrodynamic turbulence in prominences
• Shocks and instabilities in the partially ionised solar atmosphere