Conveners
Energy and mass transfer throughout the solar atmosphere and structures within
- Stanislav Gunár (Astronomical Institute of the Czech Academy of Sciences)
Energy and mass transfer throughout the solar atmosphere and structures within
- Stanislav Gunár (Astronomical Institute of the Czech Academy of Sciences)
Energy and mass transfer throughout the solar atmosphere and structures within
- Sven Wedemeyer (Rosseland Centre for Solar Physics, University of Oslo, Norway)
Energy and mass transfer throughout the solar atmosphere and structures within
- Sven Wedemeyer (Rosseland Centre for Solar Physics, University of Oslo, Norway)
Plasma flows in the near-surface region are thought to play an important role in replenishing the quiet Sun magnetic field. The interaction of magnetic fields with the complex flow structure causes these fields to reorganize at sub-granular scales. Horizontally aligned vortex flows near the edge of solar granules can grab magnetic fields from beneath and bring them to the visible surface....
Vortex flows are structures associated with the rotation of the plasma and/or the magnetic field that are present throughout the solar atmosphere, which have been detected in both numerical simulations and observations. In recent years, their study has become increasingly important, as they are present on a wide variety of temporal and spatial scales and can connect several layers of the solar...
Flux emergence in the solar atmosphere is a complex process that causes release of magnetic energy as heat and acceleration of solar plasma. We analyse imaging spectropolarimetric data taken in the He I 1083 nm line at a spatial resolution of 0.26", a time cadence of 2.8 s, and a spectral range of 150 km s$^{−1}$ around the line. This data is complemented by imaging spectropolarimetric data in...
The mechanism behind the formation of the solar penumbra remains a topic of debate, with the magnetic field configuration above the photosphere not yet thoroughly explored. In this study, we examine the formation of sunspot penumbra through a novel approach using the analysis of magnetic fields derived from Non-Linear Force-Free Field (NLFFF) extrapolations. We perform NLFFF extrapolations on...
Ellerman bombs are sites of magnetic reconnection in the deep solar atmosphere. They can be observed as strong enhancements of the hydrogen Balmer lines and display rapid variability on small spatial and temporal scales. They are typically found in young active regions with vigorous emergence of magnetic fields. High-spatial resolution observations with the Swedish 1-m Solar Telescope in La...
Small scales EUV brightening in the solar atmosphere are observed everywhere and they have been classified following a variety of observational properties. For instance, they resemble small jets, bright dots or tiny loops. X-ray and EUV observations from the existing imagers, have been used to infer, for instance, the energy budget needed to heat the solar corona, as we expect the heating...
Dark halos (DHs) are regions of reduced emission compared to the quiet Sun that are observed around active regions (ARs) at various wavelengths and wavebands, corresponding to chromosphere, transition region (TR) and corona. While in the chromosphere DHs are associated with the H$\alpha$ fibril vortex around the AR cores, in the upper atmospheric layers the origin of their dark emission is...
We present the results of coordinated observations of the Swedish 1-m Solar Telescope with Solar Orbiter that took place from October 12th to 26th 2023. The campaign resulted in 7 datasets of various quality. The observational programs were adjusted to the seeing conditions. The observations cover two active regions, a sunspot and a coronal hole. We focus on the morphology and evolution of...
At Solar Orbiter’s perihelion, the FSI telescope of the EUI instrument images the EUV corona up to 1 Rsun above the limb with a plate-scale better than 1000 km on the Sun. Here we report on exceptional FSI image sequences in the 17.4nm bandpass with deep exposures and a 30s cadence during the so-called “Density Fluctuations” and “Probe Quadrature” Solar Orbiter Observing Plans...
The radio Sun in the centimetric range (18-26 GHz) is dominated by the quiet-Sun emission, which covers the entire surface of the solar disk as a mostly uniform background. The quiet-Sun is mostly characterised by bremsstrahlung (free-free) emission at local thermal equilibrium. The solar disk at these frequencies shows dynamical chromospheric structures and phenomena -- such as Active...
Thermal non-equilibrium (TNE) is a thermodynamical state set by a stratified (mainly at the footpoints) and quasi-steady heating. It is believed to play a major role in producing a variety of very common solar phenomena, in particular: prominences, coronal rain, and long-period EUV pulsations. These two later phenomena are the two faces of the same coin: the EUV pulsations results of the...
Solar prominences are the birthplaces of coronal mass ejections, making studies of their pre-eruptive dynamics crucial for space weather. In this talk, I will review our most recent numerical studies of prominence dynamics with MPI-AMRVAC code.
Our investigation extends to the eruption evolution and the generation of coronal waves, which propagate over considerable distances through a...
It is generally believed that the chromosphere is heated by the dissipation of acoustic waves or predominantly acoustic slow modes. Here we propose that some of these essentially acoustic waves have a magnetic origin in that they are generated by torsional Alfénic pulses propagating along small-scale magnetic flux concentrations that root in the photosphere. But how do these torsional Alfvén...
Radio signals propagating via the solar corona and solar wind are significantly affected by compressive waves, impacting solar burst properties as well as sources viewed through the turbulent atmosphere. While static fluctuations scatter radio waves elastically, moving, turbulent or oscillating density irregularities act to broaden the frequency of the scattered waves. Using a new anisotropic...
In recent years, the so-called AWSOM models are a new generation of solar atmospheric models, which incorporate the heating and forces of Alfvén waves on top of more classical effects. They are outperforming older models capturing most aspects of the solar corona, but are still lacking in open field regions because of the lack of reflections and turbulence development.
In this contribution, I...
Switchbacks are large Alfvénic deflections , or even reversals, of the magnetic field in the solar wind. Many authors have suggested that switchbacks are linked to interchange reconnection in the solar corona, but the manner of this connection remains unclear. In our previous work we have shown that both the interchange reconnection process itself (Wyper et al. 22) as well as coronal jets and...
Sustained kink oscillations in coronal loops have long been observed in TRACE, SDO/AIA, and more recently in SolO/EUI images. Although their properties are quite well-known now, their driver and excitation mechanism remain under active debate. In this contribution I give an overview over recent publications and discuss how the different proposed ideas/theories for photospheric driving can be...
The mass cycle of solar prominences or filaments is still not completely understood. Researchers agree that these dense structures form by coronal in-situ condensations and plasma siphoning from the underlying chromosphere. In the evaporation-condensation model siphoning arises due to evaporation of chromospheric plasma from localised footpoint heating but this is challenging to justify...
Solar prominences are cool and dense plasma clouds suspended in the hot solar corona, supported by the magnetic field. They are common features in the solar atmosphere, but their exact formation mechanism is still unclear. We use the radiative magnetohydrodynamic code MURaM to simulate the formation and dynamics of a prominence in the solar atmosphere. MURaM includes the relevant physical...
