Description
Organisers: Tim Duckenfield, Shahin Jafarzadeh, Samuel Skirvin
Building on the UKโs legacy of groundbreaking MHD wave research, this session explores the crucial role of magnetohydrodynamic (MHD) waves in solar atmospheric dynamics and energy transport. MHD waves are powerful tools for probing plasma conditions and are thought to be key to heating the corona and driving the solar wind. This is a critical moment for MHD wave research, with new high-resolution observations from facilities like DKIST (with strong UK involvement) and SUNRISE providing unprecedented detail of magnetic oscillations across the solar atmosphere. These observations, combined with advanced modelling techniques, are revolutionising our understanding of wave generation, propagation, and dissipation across different atmospheric layers (i.e., photosphere, chromosphere, transition region, and corona) through multi-line observations and sophisticated numerical models. This session aims to connect researchers within the broad field of MHD wave research to discuss recent breakthroughs in observational, theoretical, and modelling efforts. It will provide a platform to showcase cutting-edge research using state-of-the-art facilities. In addition to the groundbreaking observations from DKIST and SUNRISE, the session will draw on the latest results from missions like Solar Orbiter, Aditya-L1, and ALMA, laying the groundwork for analysing the wealth of data soon to emerge.
Alfvรฉnic waves form a key component on the Sun's atmosphere, found to be ubiquitous in the chromosphere, corona and solar wind. While not confirmed, they are believed to play a critical role in energy transport from the convective motions out into the heliosphere;
however, many open questions remain about their journey. The DKI Solar Telescope has started providing science quality data, with...
Twisted magnetic fields in the solar chromosphere are thought to give rise to a plethora of MHD waves and flows, enabling mass and energy channelling from the photosphere to the corona. Here we report on the statistical properties of observations of waves and flows in an apparently stable but relatively large-scale spiral structure (herein referred to as a โgiant spiralโ), close to disk...
Kink oscillations in coronal loops have been extensively studied due to their potential contributions to coronal heating and their role in plasma diagnostics through coronal seismology. A key focus is the strong damping of large-amplitude kink oscillations, which observational evidence suggests is nonlinear. Yet, nonlinear damping lacks a comprehensive theoretical interpretation. This work...
Propagating slow magnetoacoustic waves, observed as intensity disturbances in extreme ultraviolet (EUV) emission, are powerful tools for magnetohydrodynamic (MHD) seismology. Their dispersive properties, phase speeds, and damping characteristics allow us to infer fundamental parameters such as temperature and magnetic field structure in coronal loops. Using observations from the Atmospheric...
The heating of the solar corona and the acceleration of the solar wind remain unresolved questions in solar physics. Previous studies have primarily focused on Alfvรฉn wave heating as the dominant mechanism, forming the basis of AWSoM models. These AWSoM models often require additional user defined processes to maintain a steady-state atmosphere. In this work, we explore kink wave heating as an...
We describe the formation of cool loops and the interaction of kink oscillations in coronal loop strands using magnetohydrodynamic simulation in ideal and non-ideal plasma regime. Firstly, we study the formation of cool loops using 2.5-dimensional MHD simulations in both adiabatic and non-adiabatic regimes. By implementing multiple transverse pulses resembling Alfvรฉn pulses, we observe the...
Alfvรฉn waves are known to be efficient carriers of magnetic energy from the Sun. Although they are linked to coronal heating and solar wind acceleration, the energy dissipation processes remain poorly constrained, particularly in open-field regions. For example, it is unclear whether a turbulent cascade of energy to the dissipation length scales is triggered in coronal conditions. Density...
Plasmas in various space objects (e.g. the solar lower atmosphere) are not hot enough to ensure a full ionisation, therefore ions, electrons and neutral particles coexist and interact with each other via collisions. Alfvรฉn waves are transversal perturbations in the magnetic field that propagate along field lines and are able to carry large amounts of energy, therefore contributing to the...
We present a 2.5D AMRVAC simulation of the magnetic Rayleigh-Taylor instability in an isolated flux tube embedded in the stratified lower solar atmosphere. The tube, denser than its surroundings, is connected to the photosphere via the magnetic field and represents a prominence within a magnetic arcade. Our study examines the plasma ฮฒ parameter's role in shaping mushroom/bubble structures,...
Recent simulations and observations often show Alfvรฉn waves in the solar atmosphere with sufficient power to heat the solar corona and accelerate the solar wind. It is long been accepted that low-frequency Alfvรฉn waves are suppressed due to inhomogeneities and steep spatial gradients in the solar atmosphere, with high-frequency waves being rapidly damped in the solar atmosphere. The effect of...
Magnetic null points are ubiquitous in the solar atmosphere, spanning from the photosphere to the corona. When perturbed, they facilitate magnetic reconnection, leading to a reconfiguration of plasma field lines and plasma heating. These structures play a crucial role in solar phenomena such as flares and coronal mass ejections. In this work we use advanced magnetohydrodynamic (MHD)...
The Sunโs transition region is a narrow layer between the hot and tenuous solar corona and the relatively dense and cool chromosphere. Across the transition region, the plasma temperature can jump by more than two orders of magnitude over a short distance. This creates significant challenges for numerical modelling, particularly in 3D, where the computational expense of including sufficient...
The coronal heating problem is one of the most important topics in solar physics. Recent advancements in observational accuracy have revealed numerous facts that cannot be explained by the conventional classical model of solar coronal heating. Among these, small-scale swirls on the photosphere, of which diameters are comparable to the resolution limits of current observational instruments,...
Solar pores unlike Sunspots are difficult to analyse, due to being much smaller in size, the absence of a penumbra and its shape evolution appearing more unstable, giving no fixed boundary of the pore. By using shape analysis tool Deformetrica created by Bone et al (2018), we can fix grid points over the shape of the pore and track the changes as it evolves over time. By doing this, we can...
