Description
Organisers: Natasha Jeffrey, Marianna Korsos, Matthew Lennard, Karen Meyer, Ryan Milligan, Rahul Sharma, Suzana Silva, Peter Wyper
The activity of our nearest star, the Sun, drives variability within the heliosphere in a myriad of different ways, impacting the Earth and other planets. As the only star on which we can begin to resolve physical processes at their intrinsic scales, the Sun provides a unique laboratory for plasma astrophysics. In this session, we welcome all contributions describing advances relating to physical processes occurring from the interior to the outer atmosphere, based on space- or ground-based observations, simulations, or theory. This session is open to all members of our community to present their work, irrespective of career level, including early-career researchers (PhD and postdoctoral).
Evaporation and condensation processes are highly dynamic in solar flares, and both can be investigated through the chromospheric spectral lines and flare ribbons.
Evaporation occurs from a source of chromospheric flare ribbon material. The key mechanism(s) driving the evaporation are not neatly resolved, with plausible candidates including non-thermal beams of particles, field-aligned...
Vortex flows in the solar photosphere are ubiquitous and are thought to inject energy into the upper solar atmosphere in the form of Poynting flux. However, observing photospheric intensity vortices is challenging due to their small size and the fact that the flow field is primarily parallel to the plane-of-sky. Despite this, a large number of photospheric intensity vortices have been observed...
Complex dynamics of a broad range of astrophysical, industrial plasmas and magnetofluids are well
described by the magnetohydrodynamic(MHD) equations.
However, due to this inherent complexity, further assumptions are often required to gain results with available resources.
A common feature of many plasmas is a strong magnetic field. One approximation that uses this assumption is called...
Current sheets play an important role in many aspects of solar and space plasma activity. For example, a vast number of collisionless current sheets can be observed in the solar wind (e.g. Vasko et al., 2022). A common problem in the context of collisionless current sheets is having to find particle distribution functions which self-consistently generate a known magnetic field profile.
We...
Understanding the properties and dynamics of energetic electrons in solar flares is critical for advancing our knowledge of flare energy release and particle acceleration. A key challenge lies in the fact that electrons of different energies are best probed by observations at different wavelengths. Hard X-ray (HXR) observations serve as powerful diagnostics for high-energy accelerated...
Solar prominences are long, cool, dense features of the solar atmosphere. Within prominences, observations and simulations both show fine threadlike structures as mass collects within the magnetic dips. We study the formation and evolution of this mass falling under gravity beneath a dense prominence region through a less dense corona under the Magnetic Rayleigh-Taylor Instability (MRTI) in...
Radiative transfer calculations have been produced over the years for many lines and continua in the UV wavelength range of the solar atmosphere for a variety of conditions. Despite significant improvements in computing power and the availability of atomic data over time, atomic models are often still limited in size and rely on approximations for data. There have also been inconsistencies in...
Ultraviolet (UV) or extreme ultraviolet (EUV) passbands, despite being relatively narrow, typically include significant contribution from multiple ions, thus leading to mixed emission from widely despairing temperature formation regimes. This is particularly limiting for diagnostic purposes of the plasma temperature, where extreme cool/hot values in the solar/stellar coronae can be attributed...
The large-scale configuration of the coronal magnetic field is central to understanding the connection between the Sun and the solar wind, for forecasting space weather, and for interpreting both in situ and remote sensing observations of the corona and beyond. Potential field source surface (PFSS) extrapolations of the observed photospheric magnetic field are invaluable and have been widely...
Magnetic activity varies over the solar cycle and is not uniformly distributed across the Sunโs surface; the latitudinal variation is clear from magnetic butterfly diagrams. Areas on the Sun with recurring flux emergence are called active region nests and show structure in longitude. These nests are thought to form due to non-axisymmetries in the generation and storage of the Sun's dynamo...
Solar flares are large eruptions of electromagnetic radiation from the Sun that can affect the Earth's atmosphere and our technologies (e.g., radio communications). Flares are identified by the arrival of their energetic photons at Earth, meaning that their space-weather effects occur at the same time we become aware that a flare is in progress - this makes it essential for us to forecast them...
Solar wind at L1 is modelled through a coupling of two independent and agnostic domains of the corona and heliosphere. The transition between the two domains occurs when the solar wind becomes supersonic and super-Alfvenic. The heliospheric solar wind is then be driven with appropriate boundary conditions at 0.1 AU which are derived from a coronal model. A popular choice for defining the...
The evolution of magnetic flux on the solar photosphere is a highly dynamic process, featuring processes such as active region emergence, which can exhibit significant variability. Since these processes may occur on the far side of the Sun, our ability to construct accurate representations of the photospheric field for coronal modelling is constrained by the limited field-of-view provided by...
Radiation remains the primary vector by which the properties of solar plasma can be investigated. Atomic spectral lines, often forming in thin atmospheric layers, offer a powerful mechanism to probe the solar atmosphere, in particular its outer layers where conditions are typically outside of local thermodynamic equilibrium. Synthesising the radiation produced by numerical models also provides...
Current sheets are plasma structures crucial to solar and space plasma processes. Kinetic-scale collisionless current sheets are readily observed in the near-Earth solar wind by in-situ measurements (e.g. Vasko et al., 2022). Finding self-consistent particle distribution functions from known magnetic field profiles is a common problem in the study of collisionless current sheets.
This...
Numerical magnetofrictional simulations are valuable tools for studying the solar coronal magnetic field and making predictions useful for forecasting space weather. Such models rely upon magnetograph observations of the emergence of new magnetic flux on the Sun, but, to date, the necessary observations have only be available from Earth. Consequently, these models can incorporate new magnetic...
Vortices are ubiquitous in the turbulent upper solar atmosphere, driving energy, mass, and momentum transport from the photosphere through the chromosphere into the corona. Observational and numerical studies reveal a hierarchy of vortex structures, from small-scale swirls in intergranular lanes, through granular-scale vortex flows, to much larger โphotospheric tornadoesโ at mesogranular...
