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).
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08/07/2025, 09:01UK Solar Physics Open SessionTalk
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...
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Shivdev Turkay (Northumbria University)08/07/2025, 09:13UK Solar Physics Open SessionTalk
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...
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Erin Goldstraw (The University of Edinburgh)08/07/2025, 09:25UK Solar Physics Open SessionTalk
Complex dynamics of a broad range of astrophysical, industrial plasmas and magnetofluids are well
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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... -
Thomas Neukirch (School of Mathematics and Statistics, University of St Andrews)08/07/2025, 09:37UK Solar Physics Open SessionTalk
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...
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YIngjie Luo (University of Glasgow)08/07/2025, 09:49UK Solar Physics Open SessionTalk
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...
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08/07/2025, 10:01UK Solar Physics Open SessionTalk
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...
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08/07/2025, 10:13UK Solar Physics Open SessionTalk
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...
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Patrick Antolin (Northumbria University)08/07/2025, 14:16UK Solar Physics Open SessionTalk
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...
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Leigh Davis (Aberystwyth University)08/07/2025, 14:28UK Solar Physics Open SessionTalk
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...
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Adam Finley (CEA Paris-Saclay)08/07/2025, 14:40UK Solar Physics Open SessionTalk
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...
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Paloma Jol (Northumbria Univeristy)08/07/2025, 14:52UK Solar Physics Open SessionTalk
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...
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Chaitanya Sishtla (Queen Mary University of London)08/07/2025, 15:04UK Solar Physics Open SessionTalk
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...
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Jonah Klowss (University of St Andrews)08/07/2025, 15:16UK Solar Physics Open SessionTalk
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...
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Christopher Osborne (University of Glasgow)08/07/2025, 15:28UK Solar Physics Open SessionTalk
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...
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UK Solar Physics Open SessionPoster
The conditions within the regions of solar flares which accelerate electrons, and the parameters that lead to those acceleration mechanisms, are not well constrained. It is not clear whether the populations accelerated out into the heliosphere and inward into the chromosphere originate in the same regions via the same mechanisms. By analysing the energy distributions of these populations, it...
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UK Solar Physics Open SessionPoster
Active regions are distinct, separable regions of the Sun where subsurface magnetic flux has emerged. The complexity of an active region's magnetic topology is a key factor in determining its likelihood of producing eruptive activity such as flares and coronal mass ejection events. However, current classification schemes, such as the widely used Mount Wilson system, are purely categorical and...
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UK Solar Physics Open SessionPoster
One of the fundamental structures found within the solar corona are loops of dense plasma and high magnetic flux. Under the extreme conditions found within the solar atmosphere, thermal transport can both become limited and non-local. An MHD code, with a non-local thermal conduction model included is used to investigate its effect on the solar atmosphere. In particular it is used to simulate a...
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Thomas Neukirch (School of Mathematics and Statistics, University of St Andrews)UK Solar Physics Open SessionPoster
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...
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UK Solar Physics Open SessionPoster
Bright points (BPs) are ubiquitous, small-scale energetic events with a multithermal nature, typically observed in the chromosphere and closely linked to the photosphere and corona. Their evolution is influenced by plasma dynamics and magnetic interactions.
This work analyzes BP evolution over time, focusing on when they reach peak attribute values. Key characteristics examined include...
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UK Solar Physics Open SessionPoster
Non-thermal acceleration of particles in the solar corona is evident from both remote hard X-ray (HXR) and in-situ observations of high-energy emission, however the plasma and turbulent properties of the source acceleration region(s) are not fully understood. Correlation of spectral indices from these two population suggests the existence of a common source region in the corona. To better...
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UK Solar Physics Open SessionPoster
Since 2023, the IRIS mission has run a very high cadence flare observing programme, enabling sub-second timescales to be observed in sit-and-stare mode. This poster will report on initial timing analysis of flare radiation, focussing on very prompt signatures of flare energy input. These include electron density and ionisation changes, and fluorescent emission in the mid-to-low chromosphere....
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UK Solar Physics Open SessionPoster
X-ray emission is released by both the heated plasma and accelerated electrons in solar flares, making it an important diagnostic of the impulsive energy release. Through joint multi-instrumental X-ray observations of solar flares we can get better constraints on the observed emission and gaining a better understanding of the energy release. We present summary of the results from the first...
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Aaron W. Peat (University of Wrocลaw)UK Solar Physics Open SessionPoster
Using 2D Mgษชษช h&k solar prominence modelling, we aim to understand the formation of complex line profiles and how these are seen by the Interface Region Imaging Spectrograph (IRIS). Additionally, we see how the properties of these simulated observations are interpreted by traditional 1D prominence modelling. A cylindrical NLTE (i.e. departures from local thermodynamic equilibrium) 2D complete...
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UK Solar Physics Open SessionPoster
We study the behaviour of the fast magnetoacoustic wave in a magnetic topology containing an X-type null point and focus on the propagation of these waves in close proximity to the null point. We use the Lare2D numerical code to drive a linear fast magnetoacoustic wave into the topology, and investigate the behaviour, finding that the Alfvรฉn speed profile plays a critical role. We also solve...
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UK Solar Physics Open SessionPoster
The magnetic field in the solar corona plays a dominant role in determining the dynamics of the high temperature, low density coronal plasma. Despite the importance of the coronal magnetic field, there is a distinct lack of analytical models based on empirical data. How fast the magnetic field expands with height is known as the expansion factor and this is intrinsically related to the...
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Lauren McClure (The University of Sheffield)UK Solar Physics Open SessionPoster
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...
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