Parallel sessions

Since Grotrian (1939) discovered 'forbidden lines' of iron in the Sun's emission spectrum, the question of what sustains the multi-million-degree temperatures in the solar atmosphere has been one of the most significant and enduring questions in solar physics. Most proposed solutions involve a crucial role for the magnetic field. On short, oscillatory timescales, it supports a mixture of waves, which carry energy into the corona that can then dissipate. On longer timescales, it allows the build-up of magnetic energy, which is then explosively released by instabilities and magnetic reconnection. Both can lead to a cascade to shorter length scales, bringing about the onset of plasma and MHD turbulence. All of the micro-physical processes involved on these short length scales are poorly understood. Increasingly sophisticated theories propose new explanations for them. Prominently, magnetic reconnection on the Sun is now far better understood, in terms of the tearing mode, having developed from early concepts of Sweet and Parker. Through the combination of new numerical techniques, growing computational power, and greater insight into the underlying physics, numerical models have similarly advanced. Now, they can study the onset of these processes, and their dynamic, non-linear evolution, with increasing accuracy. Recent, state-of-the-art facilities and instruments, such as DKIST, Solar Orbiter, and the Parker Solar Probe, give a new perspective on the physical processes underway in heating the solar atmosphere. With closer physical proximity and finer optical resolution, they shed new light on the conditions in which these several processes commence, as well as their dynamic and thermodynamic aftermath. Theoretical and numerical conjectures can then be tested and assessed against these results. Therefore, this session will explore coronal heating by magnetohydrodynamic and micro-physical instabilities, standing and propagating waves, and plasma turbulence. Complex behaviours that contribute to coronal heating will be discussed, informed by the latest advances in theory, numerical modelling, and observations. Convergence between these approaches will advance our understanding of the processes that release energy in the atmosphere and maintain coronal temperatures.