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Peter Wyper

Publications and source records attributed to Peter Wyper.

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UK White Paper on Space-based total solar eclipse observations: structure and dynamics of the solar atmosphere

Our Sun is uniquely placed to enable a detailed study of astrophysical plasmas and how they are governed by the magnetic fields that thread through them. On the one hand, magnetic fields confine plasma and determine plasma heating, flows, and energisation. On the other hand, magnetic fields and their evolution give rise to the most violent eruptions in the Solar System. Understanding the details of how energy is built up and released, and the impact of these physical processes on the plasma, remain key open questions that directly map to UKRI's science strategy through the STFC Solar System Advisory Panel's roadmap for Solar System research goals: What are the causes, consequences and predictability of solar magnetic variability and the solar cycle? What are the structures, dynamics and energetics of the Sun? What are the underlying processes that drive Sun-planet connections? And what are the fundamental processes at work in the Solar System? As laid out in this White Paper, the Moon-Enabled Sun Occultation Mission (MESOM) directly addresses these questions and in doing so delivers several Pillars of the National Space Strategy.

astro-ph.IM

Investigation of magnetic topology and triggering mechanisms of a C-class flare and active-region blowout jet

Coronal jets are collimated plasma eruptions which are ubiquitous in the solar atmosphere. Believed to be triggered by magnetic reconnection, these jets can contribute to various phenomena, including coronal heating and particle acceleration. Coronal jets are a contemporary area of research with their onset mechanism meriting further attention. Importantly, a subclass of jets, the blowout jets, are particularly interesting because of their broad spire, suggesting substantial three-dimensional (3D) reconnection between open and closed field lines involving 3D null points. Consequently, here we explore the onset of a blowout jet associated with Active Region (AR) SPoCA 29093 detected by Spatial Possibilistic Clustering Algorithm (SPoCA). This AR produced a C1.1-class flare on 10 November 2022 and we investigate it using a data-constrained magnetohydrodynamic simulation initiated with a non force-free-field (NFFF) extrapolation of the photospheric magnetic field. Key elements of the extrapolated field lines are the presence of a 3D null and a magnetic flux rope (MFR) co-located with the jet activity region, the evolution of which is further traced in the simulation. The simulation suggests that magnetic reconnection is responsible for the evolution of the MFR, leading to a near-simultaneous onset of the flare and jet as observed by the AIA/SDO. In particular, the simulation shows spontaneous creation and annihilation of 3D null pairs via magnetic reconnection near the jet region. Such spontaneous null pair generation, in principle, can trigger or contribute to coronal jets; opening up a new avenue for further research.

astro-ph.SR

UK White Paper on Magnetic Reconnection

Magnetic reconnection powers explosive releases of magnetic energy, heating and particle acceleration throughout the plasma universe. Knowledge of this universal process is vital to understanding the Heliosphere, as it plays a key role in solar flares, coronal mass ejections, coronal heating, solar wind acceleration, geomagnetic storms, and interactions between the solar wind and planetary magnetospheres. As such, reconnection underpins multiple science objectives of multiple future space missions. The UK plays a leading role in this international field, through a combination of in situ measurements from Earth's magnetosphere and the solar wind, observations of the solar corona and chromosphere, and world-class numerical simulations and theory. This white paper identifies: Nine priority science objectives for reconnection research in the next decade; Recommendations to guide investment in theory, simulations and infrastructure; Mission priorities and required measurements to ensure the UK maintains and improves its world-class credentials in reconnection science.

astro-ph.IM