Frozen-field Modeling of Coronal Condensations with MPI-AMRVAC. II. Optimization and Application in 3D Models DOI Creative Commons
Y. Zhou, Xiaohong Li, J. M. Jenkins

et al.

The Astrophysical Journal, Journal Year: 2024, Volume and Issue: 978(1), P. 72 - 72

Published: Dec. 26, 2024

Abstract The frozen-field hydrodynamic (ffHD) model is a simplification of the full magnetohydrodynamical equations under assumption rigid magnetic field, which significantly reduces computational complexity and enhances efficiency. In this work, we combine ffHD prescription with hyperbolic thermal conduction (TC) Transition Region Adaptive Conduction (TRAC) method to achieve further optimization. A series 2D tests are done evaluate performance TC TRAC method. results indicate that TC, while showing limiter-affected numerical dissipation, delivers outcomes comparable classic parabolic TC. effectively compensates for underestimation enthalpy flux in low-resolution simulations, as evaluated on demonstrate prominence formation. We present an application forms 3D embedded rope, develops into stable slab-like filament. simulation reveals elongated spine width consistent observations, highlighting potential capturing dynamics solar prominences. Forward modeling data produces synthetic images at various wavelengths, providing insights appearance prominences filaments different observational contexts. model, its efficiency demonstrated capability simulate complex phenomena, offers valuable tool physicists, implemented open-source MPI-AMRVAC framework.

Language: Английский

Modeling the Solar Transition Region: Effects of Spatial Resolution on the Atmospheric Structure, Emission and Non-equilibrium Ionization DOI Creative Commons
Takuma Matsumoto

The Astrophysical Journal, Journal Year: 2025, Volume and Issue: 983(1), P. 71 - 71

Published: April 7, 2025

Abstract The solar transition region (TR) is a narrow interface between the chromosphere and corona, where emitted radiation contains critical information pertinent to coronal heating processes. We conducted two-dimensional magnetohydrodynamics simulations using adaptive mesh refinement spatially resolve fine structure of TR while simultaneously capturing larger-scale dynamics originating from surface convection. time evolution ionization fractions for oxygen ions computed alongside simulations. A minimum grid size 1.25 km achieved in TR, enabling adequate resolution upper (log 10 T ≳ 5), although lower ≲ 5) remains under-resolved. Doppler shifts nonthermal widths synthesized lines exhibit convergence with sizes as coarse 40 km, though some discrepancies persist our results observed line properties. notable enhancement emission O vi lines, converging at 2.5 shows an intensity 1.2 times that expected under equilibrium, attributable shock interactions TR. While model refinements are still required, ability offers insights into characteristics arising non-equilibrium states, advancing understanding problem.

Language: Английский

Citations

0
Characteristics and energy flux distributions of decayless transverse oscillations depending on coronal regions DOI Creative Commons
Daye Lim, Tom Van Doorsselaere, D. Berghmans

et al.

Astronomy and Astrophysics, Journal Year: 2024, Volume and Issue: 689, P. A16 - A16

Published: June 18, 2024

Context. It has been proposed that the slope ( δ ) of power-law distribution between energy flux and oscillation frequency could determine whether high-frequency transverse oscillations make a dominant contribution to heating < 1). A meta-analysis decayless revealed potentially play key role in solar corona. Aims. We aim investigate or not (and, if so, how) distributions contained oscillations, their slopes, depend on coronal region which occurs. Methods. analysed from 41 quiet Sun (QS) loops 22 active (AR) observed by Solar Orbiter/Extreme Ultraviolet Imager (EUI) HRI EUV . estimated using parameters loop properties, such as periods, displacement amplitudes, lengths, minor radii loops. Results. find about 71% QS 86% AR show amplitude does change depending different regions, but difference period is more pronounced. Although power law = −1.79) steeper than −1.59) QS, both them are significantly less critical 1. Conclusions. Our statistical study demonstrates can heat QS. For ARs, total insufficient unless yet-unobserved with frequencies up 0.17 Hz present. Future EUI campaigns will be planned confirm corresponding exists.

Language: Английский

Citations

2
Decayless oscillations in 3D coronal loops excited by a power-law driver DOI Creative Commons
Konstantinos Karampelas, Tom Van Doorsselaere

Astronomy and Astrophysics, Journal Year: 2023, Volume and Issue: 681, P. L6 - L6

Published: Dec. 12, 2023

Aims. We studied the manifestation of decayless oscillations in 3D simulations coronal loops, driven by random motions. Methods. Using PLUTO code, we ran magnetohydrodynamic (MHD) a straight gravitationally stratified flux tube, with its footpoints embedded chromospheric plasma. consider transverse waves drivers horizontally polarised red noise power-law spectrum. Results. Our broadband lead to excitation standing frequencies equal fundamental kink mode and harmonics. These have non-decaying amplitudes, spectra that depend on characteristics latter amplifying resonant from drivers. thus report for first time The spatial temporal evolution our oscillation reveals half harmonic, which exhibits frequency identified similar profile. results suggest this is related presence transition region model could be interpreted as being equivalent sound pipes closed at one end. Conclusions. potential existence harmonic has important implications seismology, since misinterpreting it system can false estimations average speed profile along oscillating loops. Finally, detection potentially give us tool distinguishing between different driving mechanisms observations.

Language: Английский

Citations

6
Kelvin-Helmholtz instability and heating in oscillating loops perturbed by power-law transverse wave drivers DOI Creative Commons
Konstantinos Karampelas, Tom Van Doorsselaere, Mingzhe Guo

et al.

Astronomy and Astrophysics, Journal Year: 2024, Volume and Issue: 688, P. A80 - A80

Published: June 4, 2024

Instabilities in oscillating loops are believed to be essential for dissipating the wave energy and heating solar coronal plasma. Our aim is study development of Kelvin-Helmholtz (KH) instability an loop that driven by random footpoint motions. Using PLUTO code, we performed 3D simulations a straight gravitationally stratified flux tube. The footpoints embedded chromospheric plasma, presence thermal conduction artificially broadened transition region. drivers with power-law spectrum, one red noise spectrum low-frequency part subtracted, excited standing oscillations KH our loops, after one-and-a-half periods oscillation. We see broadband lead fully deformed, turbulent cross-sections over entire due spatially extended instability. low RMS velocity driver without components supports working hypothesis can easily manifest loops. report first time transverse apparent propagation density perturbations onset instability, from apex towards footpoints. Both input sufficient drive enthalpy mass fluctuations along loop, while also causing near which becomes more prominent when component included driver. Finally, provides Poynting same order as radiative losses quiet-Sun corona, giving us promising prospects contribution decayless heating.

Language: Английский

Citations

1
Modelling the connection between propagating disturbances and solar spicules DOI Creative Commons
Samuel Skirvin, Tanmoy Samanta, Tom Van Doorsselaere

et al.

Astronomy and Astrophysics, Journal Year: 2024, Volume and Issue: 689, P. A135 - A135

Published: June 27, 2024

Aims. Propagating (intensity) disturbances (PDs) have been extensively reported in observations of coronal loops and polar plumes, along with more recent links to co-temporal spicule activity the solar atmosphere. However, despite their appearance observations, PDs yet be studied or modelled depth. Methods. In this work, we present results from a three-dimensional magnetohydrodynamic (3D MHD) numerical model. It features stratified atmosphere perturbed by p -mode wave driver at photosphere, subsequently forming spicules described rebound shock Results. We find detected consistent transition region dynamics spicular resulting non-linear steepening formation. Furthermore, could interpreted as slow magnetoacoustic pulses propagating magnetic field, rather than high-speed plasma upflows carrying sufficient energy flux (at least partially) heat lower plasma. Using forward modelling, demonstrate similarities between simulations those IRIS SDO/AIA. Conclusions. Our suggest that model presented here, dynamical movement is result formation are launched co-temporally rising region, regardless wave-generating physical mechanisms occurring underlying it clear signatures appear much clearer when photospheric included. Finally, importance context providing source for powering (fast) wind.

Language: Английский

Citations

1
The evolution of the coronal loop structure due to the phase mixing of high and low frequency Alfvén waves DOI Creative Commons

H Callingham,

I. De Moortel, P. Pagano

et al.

Monthly Notices of the Royal Astronomical Society, Journal Year: 2024, Volume and Issue: 535(2), P. 1640 - 1651

Published: Oct. 29, 2024

ABSTRACT Coronal loops are known to host Alfvén waves propagating in the corona from lower layers of solar atmosphere and because their internal structure, phase mixing is likely occur. The structure coronal loop could be significantly affected by thermodynamic feedback heating generated mixing. However, this phenomenon can sensitive period due how short easily dissipated way long-period may accumulate considerable energy resonating loops. Using Lare2d code, a model field-aligned equilibrium cross-field background profile created, with an additional forcing term added drive amplitudes between $5{\!-\!}30 \, \mathrm{km} \mathrm{s}^{-1}$. We show that high-frequency generate corresponding ${\sim} 10~{{\ \rm per\ cent}}$ increase initial shell temperature, chromospheric upflows up $0.6 \mathrm{s}^{-1}$ mass 15~{{\ cent}}$. These changes sufficient alter maintain new density broadening region where efficient (and therefore heating) occurs. In contrast, low-frequency unable effectively dissipated, resulting minimal structure. see little evidence wave accumulation conclude dissipation effective mechanism setup used study.

Language: Английский

Citations

0
Investigating numerical stability by scaling heat conduction in a 1D hydrodynamic model of the solar atmosphere DOI Creative Commons
Vartika Pandey, Philippe-A. Bourdin

Astronomy and Astrophysics, Journal Year: 2024, Volume and Issue: 693, P. A89 - A89

Published: Dec. 11, 2024

Context. Numerical models of the solar atmosphere are widely used in research and provide insights into unsolved problems such as heating coronal loops. A prerequisite for simulations is an initial condition plasma temperature density. Many explicit numerical schemes employ high-order derivatives that require some diffusion, example isotropic each independent variable to maintain stability. Otherwise, significant inaccuracies subsequent wiggles will occur grow at steep gradients transition region. Aims. We tested how adapt heat conduction grid resolution so model capable resolving varying gradients. Our ultimate goal construct atmospheric stratification can serve multi-dimensional models. Methods. spans from interior outer corona. From that, we computed hydrostatic density stratification. Since analytical not identical, needs settle a equilibrium fit all parameters, mass diffusion radiative losses. To compensate energy losses corona, implemented artificial function mimics expected input 3D field-line braiding mechanism. Results. maintains stabilises obtained However, diffusivity parameters need be adapted spacing. Unexpectedly, find higher resolutions may larger diffusivities – contrary common understanding high-resolution automatically more realistic would less diffusivity. Conclusions. Smaller spacing causes region hence greater potential problems. conclude efficient remedy when using with derivatives.

Language: Английский

Citations

0
Frozen-field Modeling of Coronal Condensations with MPI-AMRVAC. II. Optimization and Application in 3D Models DOI Creative Commons
Y. Zhou, Xiaohong Li, J. M. Jenkins

et al.

The Astrophysical Journal, Journal Year: 2024, Volume and Issue: 978(1), P. 72 - 72

Published: Dec. 26, 2024

Abstract The frozen-field hydrodynamic (ffHD) model is a simplification of the full magnetohydrodynamical equations under assumption rigid magnetic field, which significantly reduces computational complexity and enhances efficiency. In this work, we combine ffHD prescription with hyperbolic thermal conduction (TC) Transition Region Adaptive Conduction (TRAC) method to achieve further optimization. A series 2D tests are done evaluate performance TC TRAC method. results indicate that TC, while showing limiter-affected numerical dissipation, delivers outcomes comparable classic parabolic TC. effectively compensates for underestimation enthalpy flux in low-resolution simulations, as evaluated on demonstrate prominence formation. We present an application forms 3D embedded rope, develops into stable slab-like filament. simulation reveals elongated spine width consistent observations, highlighting potential capturing dynamics solar prominences. Forward modeling data produces synthetic images at various wavelengths, providing insights appearance prominences filaments different observational contexts. model, its efficiency demonstrated capability simulate complex phenomena, offers valuable tool physicists, implemented open-source MPI-AMRVAC framework.

Language: Английский

Citations

0