Organisational Resilience for Severe Space Weather

This special report is the result of a collaboration between academics and practitioners. It aims to assess and identify organisational mitigation strategies to respond to space weather events and any associated technological disruptions. The format aims to provide an overview in order to facilitate reading in conditions of limited availability of time. The following topics are addressed: • An introduction to severe space weather events and their possible impacts. • A risk assessment process and discussion of vulnerabilities that are common with other threats. • Illustrative examples. • An operational checklist for continuity planning and management. • Basic actions to increase organisational and operational resilience. • Resources for training and essential references

Simulating the coronal evolution of bipolar active regions to investigate the formation of flux ropes

Funding: S.L.Y. would like to acknowledge STFC for support via the Consolidated Grant SMC1/YST025. D.H.M. would like to thank STFC, the Leverhulme Trust and the ERC under the Synergy Grant: The Whole Sun, grant agreement no. 810218 for financial support. L.M.G. is thankful to the Royal Society for a University Research Fellowship and the Leverhulme Trust.The coronal magnetic field evolution of 20 bipolar active regions (ARs) is simulated from their emergence to decay using the time-dependent nonlinear force-free field method of Mackay, Green, and van Ballegooijen (Astrophys. J. 729, 97, 2011). A time sequence of cleaned photospheric line-of-sight magnetograms, which covers the entire evolution of each AR, is used to drive the simulation. A comparison of the simulated coronal magnetic field with the 171 and 193 Å observations obtained by the Solar Dynamics Observatory (SDO)/Atmospheric Imaging Assembly (AIA), is made for each AR by manual inspection. The results show that it is possible to reproduce the evolution of the main coronal features such as small- and large-scale coronal loops, filaments and sheared structures for 80% of the ARs. Varying the boundary and initial conditions, along with the addition of physical effects such as Ohmic diffusion, hyperdiffusion and a horizontal magnetic field injection at the photosphere, improves the match between the observations and simulated coronal evolution by 20%. The simulations were able to reproduce the build-up to eruption for 50% of the observed eruptions associated with the ARs. The mean unsigned time difference between the eruptions occurring in the observations compared to the time of eruption onset in the simulations was found to be ≈5 hrs. The simulations were particularly successful in capturing the build-up to eruption for all four eruptions that originated from the internal polarity inversion line of the ARs. The technique was less successful in reproducing the onset of eruptions that originated from the periphery of ARs and large-scale coronal structures. For these cases global, rather than local, nonlinear force-free field models must be used. While the technique has shown some success, eruptions that occur in quick succession are difficult to reproduce by this method and future iterations of the model need to address this.Publisher PDFPeer reviewe

Stealth Coronal Mass Ejections from Active Regions

Stealth coronal mass ejections (CMEs) are eruptions from the Sun that have no obvious low coronal signature. These CMEs are characteristically slower events, but can still be geoeffective and affect space weather at Earth. Therefore, understanding the science underpinning these eruptions will greatly improve our ability to detect and, eventually, forecast them. We present a study of two stealth CMEs analysed using advanced image processing techniques that reveal their faint signatures in observations from the extreme ultraviolet (EUV) imagers onboard the Solar and Heliospheric Observatory (SOHO), Solar Dynamics Observatory (SDO), and Solar Terrestrial Relations Observatory (STEREO) spacecraft. The different viewpoints given by these spacecraft provide the opportunity to study each eruption from above and the side contemporaneously. For each event, EUV and magnetogram observations were combined to reveal the coronal structure that erupted. For one event, the observations indicate the presence of a magnetic flux rope before the CME's fast rise phase. We found that both events originated in active regions and are likely to be sympathetic CMEs triggered by a nearby eruption. We discuss the physical processes that occurred in the time leading up to the onset of each stealth CME and conclude that these eruptions are part of the low-energy and velocity tail of a distribution of CME events, and are not a distinct phenomenon.Comment: 20 pages, 10 figures, accepted for publication in The Astrophysical Journa

Pathways to parenting stress reduction among parents in South Africa

Parenting stress has a range of effects on parents and their children. Despite existing evidence on the effectiveness of family-based interventions on reducing parenting stress, little is known about the mechanism of change that contributes to its reduction. This study investigates the mechanism of change in a parenting programme (Parenting for Lifelong Health [PLH]) on reducing parenting stress among parents of adolescents in South Africa. A pragmatic cluster randomized controlled trial was conducted among a total sample of 552 parents and primary caregivers (aged, M = 49.37; SD = 14.69) who were recruited from 40 communities in South Africa's Eastern Cape Province. A mediation analysis was performed to investigate direct and indirect effects using PROCESS macrostatistical software. The findings of the study indicate that parenting stress reduction operates via three significant mediators: improved parent–child relationship (β = 0.058, P β = −0.103, P β = −0.049, P

Optical Design of a Miniaturised Solar Magnetograph for Space Applications

Measuring the Sun’s magnetic field is a key component of monitoring solar activity and forecasting space weather. The main goal of the research presented in this paper is to investigate the possibility of reducing the dimensions and weight of a solar magnetograph while preserving its optical quality. This article presents a range of different designs, along with their advantages and disadvantages, and an analysis of the optical performance of each. All proposed designs are based on the magneto-optical filter (MOF) technique. As a result of the design study, a miniaturised solar magnetograph is proposed with an ultra-compact layout. The dimensions are 345 mm × 54 mm × 54 mm, and the optical quality is almost at the diffraction limit. The design has an entrance focal ratio of F/17.65, with a plate scale of 83.58 arcsec/mm at the telescope image focal plane, and produces a magnification of 0.79. The field of view is 1920 arcsec in diameter, equivalent to ±0.27 degrees, sufficient to cover the entire solar disk

The Nature of Queer Desire in Céline Sciamma’s Filmography

This thesis explores Céline Sciamma’s five feature films Naissance des pieuvres (2007), Tomboy (2011), Bande de filles (2014), Portrait de la jeune fille en feu (2019) and Petite Maman (2021). Central to this thesis is Sciamma’s focus on queer narratives, as she demonstrates the fluidity of queerness as characters grow and explore themselves. Thus, this thesis uses cultural studies to focus on themes of gender, sexuality, queernesss, desire and nature. Ultimately, this text considers how Sciamma uses nature as an allegory for queerness. Split into four chapters, this thesis uses the four elements (water, earth, air and fire) as a framework, proposing that Sciamma uses each of these elements allegorically throughout her films. The thesis argues that Sciamma uses the four elements to naturalise queer desire as it explores the intersection between ecology and queerness through a close textual-analysis and reading of Sciamma’s films. The first chapter investigates Sciamma’s use of water, examining its symbolic use to display the fluidity of queerness in addition to the performative nature of gender within spaces of bathrooms, swimming pools and lakes. Chapter two studies the element earth to explore Sciamma’s use of rural and urban spaces, examining how she creates queer chronotopes within her films. This thesis then moves on to analyse the role of air. To do this, the chapter acknowledges how pain and eroticism are displayed through the breath and then examines how sound and silence play an important role in Sciamma’s representation and naturalisation of queerness. Finally, this thesis focuses on the element fire by considering the creative and destructive dichotomy of the element, in addition to discussing the manifestations of fire through lighting, food, warmth and passion

The magnetic field environment of active region 12673 that produced the energetic particle events of September 2017

Forecasting solar energetic particles (SEPs), and identifying flare/CMEs from active regions (ARs) that will produce SEP events in advance is extremely challenging. We investigate the magnetic field environment of AR 12673, including the AR's magnetic configuration, the surrounding field configuration in the vicinity of the AR, the decay index profile, and the footpoints of Earth-connected magnetic field, around the time of four eruptive events. Two of the eruptive events are SEP-productive (2017 September 4 at 20:00~UT and September 6 at 11:56~UT), while two are not (September 4 at 18:05~UT and September 7 at 14:33~UT). We analysed a range of EUV and white-light coronagraph observations along with potential field extrapolations and find that the CMEs associated with the SEP-productive events either trigger null point reconnection that redirects flare-accelerated particles from the flare site to the Earth-connected field and/or have a significant expansion (and shock formation) into the open Earth-connected field. The rate of change of the decay index with height indicates that the region could produce a fast CME ($v >$ 1500~km~s$^{-1}$), which it did during events two and three. The AR's magnetic field environment, including sites of open magnetic field and null points along with the magnetic field connectivity and propagation direction of the CMEs play an important role in the escape and arrival of SEPs at Earth. Other SEP-productive ARs should be investigated to determine whether their magnetic field environment and CME propagation direction are significant in the escape and arrival of SEPs at Earth.Comment: Accepted in ApJ, 18 pages, 8 Figures, 2 Table

Mediation pathways for reduced substance use among parents in South Africa:A randomized controlled trial

Background: Substance use is a major public health concern worldwide. Alcohol and drug use have increased during recent decades in many low- and middle-income countries, with South Africa, where this study was conducted, having among the highest rates in the world. Despite existing evidence on the effectiveness of family-based interventions in reducing substance use among parents and caregivers in low- and middle-income countries, little is known about the mechanism of change that contributes to the reduction. This study investigated mediators of change in a parenting programme (Parenting for Lifelong Health [PLH]) on reducing substance use among parents and caregivers of adolescents through three potential mediators: parental depression, parenting stress and family poverty. Methods: The current study used a pragmatic cluster randomized controlled trial design. The total sample comprised 552 parent and caregiver of adolescents M = 49.37(SD = 14.69) who were recruited from 40 communities in South Africa’s Eastern Cape. Participants completed a structured confidential self-report questionnaire at baseline and a follow-up test 5 to 9 months after the intervention. Structural equation modeling was conducted to investigate direct and indirect effects. Results: Analyses indicated that the effect of the PLH intervention on reducing parental substance use was mediated in one indirect pathway: improvement in parental mental health (reduction in parental depression levels). No mediation pathways from the PLH intervention on parental substance use could be associated with parenting stress or family poverty. Conclusions: The findings of the study suggest that intervention approaches targeting mental health among parents and caregivers have promise for reducing parental substance use. These findings emphasize the need to create supportive environments and systems for parents who suffer from emotional strain and mental health problems, particularly within families experiencing adversity. Trial registration: Pan-African Clinical Trials Registry PACTR201507001119966. Registered on 27 April 2015. The trial can be found by searching for the key word ‘Sinovuyo’ on the Pan-African Clinical Trials Registry website or via the following link: http://www.pactr.org/ATMWeb/appmanager/atm/atmregistry?_nfpb=true&_windowLabel=BasicSearchUpdateController_1&BasicSearchUpdateController_1_actionOverride=%2Fpageflows%2Ftrial%2FbasicSearchUpdate%2FviewTrail&BasicSearchUpdateController_1id=111

The Merging of a Coronal Dimming and the Southern Polar Coronal Hole

We report on the merging between the southern polar coronal hole and an adjacent coronal dimming induced by a coronal mass ejection on 2022 March 18, resulting in the merged region persisting for at least 72 hr. We use remote sensing data from multiple co-observing spacecraft to understand the physical processes during this merging event. The evolution of the merger is examined using Extreme-UltraViolet (EUV) images obtained from the Atmospheric Imaging Assembly on board the Solar Dynamic Observatory and Extreme Ultraviolet Imager, which is on board the Solar Orbiter spacecraft. The plasma dynamics are quantified using spectroscopic data obtained from the EUV Imaging Spectrometer on board Hinode. The photospheric magnetograms from the Helioseismic and Magnetic Imager are used to derive the magnetic field properties. To our knowledge, this work is the first spectroscopical analysis of the merging of two open-field structures. We find that the coronal hole and the coronal dimming become indistinguishable after the merging. The upflow speeds inside the coronal dimming become more similar to that of a coronal hole, with a mixture of plasma upflows and downflows observable after the merging. The brightening of the bright points and the appearance of coronal jets inside the merged region further imply ongoing reconnection processes. We propose that component reconnection between the coronal hole and coronal dimming fields plays an important role during this merging event because the footpoint switching resulting from the reconnection allows the coronal dimming to intrude onto the boundary of the southern polar coronal hole