Dynamics of Complex Magnetic Fields: From the corona to the solar wind

Lead Research Organisation: University of Dundee
Department Name: Mathematics

Abstract

This project, entitled "Dynamics of Complex Magnetic Fields: From the corona to the solar wind'', is a continuation of a successful collaboration between the researchers of the Universities of Dundee and Durham on the entangled nature of magnetic fields in the solar atmosphere. The corona, the outer atmosphere of the Sun, is a dynamic plasma permeated by a magnetic field. This magnetic field is responsible for creating long-lived structures such as coronal loops, for heating the corona to its multi-million degree temperatures, and for explosive events such as solar flares and coronal mass ejections. These powerful explosions lead to major space weather events at Earth, creating the Northern and Southern lights but also having the potential for damaging economic impacts on engineered systems, ranging from satellites and communication systems to power grids and pipelines. It is becoming apparent that forecasting the occurrence and impact of space weather events cannot rely on static extrapolation models but requires a deep understanding of the dynamical behaviour of the Sun's magnetic field. Details of the complex, three-dimensional magnetic fields in the Sun's corona are a critical part of the space weather chain of events. At the same time, it is important to understand the manner in which these magnetic structures evolve in the solar wind as they are carried out towards Earth. This consortium aims to address these questions, as part of a wider goal in the scientific community of understanding the formation of structures in astrophysical plasmas.

Different projects within the consortium will focus on different aspects of the chain of events. We will address problems such as: How can we best model the build-up of coronal magnetic structure over time? What is the nature of the twisted magnetic "flux ropes" that form in the corona, and how does their structure evolve as they erupt and form coronal mass ejections? Where is the source of the non-steady slow component of the solar wind? What is the mechanism that makes the Sun's corona so hot? What controls the lowest energy state to which the coronal magnetic field can relax, and therefore how much energy is available to heat the plasma? Can we predict the equilibrium structure of the corresponding relaxed states? Common to each of these questions is the challenge of understanding dynamical, multi-scale processes in the Sun's coronal magnetic field.

We will use a combination of numerical simulations and mathematical modelling to tackle these questions, primarily using the non-linear partial differential equations of magnetohydrodynamics. Importantly, the modelling will take input from the latest generation of solar telescopes - several of our models will be directly "data-driven", and observations will be used to validate output (from global simulations of the coronal magnetic field to predictions of the slow solar wind and structure of magnetic clouds at Earth). Combined, the results will help to predict and explain events in the solar corona and to answer STFC's Science Roadmap Challenge B:2 ("How does the Sun influence the environment of the Earth and the rest of the Solar System?"), as well as to understand some of the basic plasma physical processes that go on throughout the Universe.

Planned Impact

Eruptive magnetic storms on the Sun (Coronal Mass Ejections) regularly reach the Earth's space environment. The economic consequences of this space weather can be severe, and include damage to satellites and power grids, corrosion of oil and gas pipelines and disruption of communication systems. Furthermore, these events may endanger the health of astronauts and those onboard high-flying aircraft. The proposed research seeks to develop an understanding of how complex magnetic structures in the Sun's atmosphere change and interact, with these interactions being a critical part of the chain of events that generates solar eruptions. As such, a possible major impact of the proposed research will be on the international effort to develop reliable space-weather forecasting systems. (Given notice, defensive measures can be taken against the aforementioned effects.)

Project 1.1, examining the dynamics of the global solar corona, will allow for significantly improved simulations of the Sun's magnetic field on global scales. This will have potential impacts both on short-term space weather forecasting and on reconstructions of the Sun's magnetic field in the past which, in turn, will affect reconstructions of the Earth's climate in the past. Similarly Projects 1.2 and 1.3, on the slow solar wind and the structure of magnetic flux ropes ejected from the Sun, will both help to improve our knowledge of the space weather in proximity of the Earth.

Projects 1.4 and 1.5 investigate the dynamics and structure of complex magnetic fields, a fundamental problem of astrophysical and laboratory plasmas (e.g., in controlled thermonuclear fusion). This research in particular - and the other projects to a lesser extent - should be seen in the wider framework of the analysis of complex multi-scale systems which we encounter in many areas of science: the weather, cellular networks, material sciences, neurosciences, nuclear sciences, etc. The theoretical tools and methods created for investigating astrophysical plasmas have both benefited from and contributed to progress in these areas, via exchanges of ideas, software and human resources.

More generally, astronomy has a strong cultural impact. Due to the Sun's close proximity and the stunning images being gathered by new satellites, solar physics has a great capacity to get young people interested in science, contributing to UK's skilled labour market. We will engage with schools and the general public on our research findings through the Schools Outreach Programme of the Division of Mathematics in Dundee, via press releases, articles in popular science magazines and public events such as the Dundee Science Festival. These methods are further documented in the Outreach section of the Impact Plan document.

Publications

10 25 50
 
Description IAU travel support for S. Candelaresi
Amount £652 (GBP)
Organisation International Astronomical Union 
Sector Learned Society
Country France
Start 10/2016 
End 10/2016
 
Description IAU travel support for S. Candelaresi
Amount € 740 (EUR)
Funding ID IAU327 
Organisation International Astronomical Union 
Sector Learned Society
Country France
Start 10/2016 
End 10/2016
 
Description INI visitor support
Amount £500 (GBP)
Organisation Isaac Newton Institute for Mathematical Sciences 
Sector Academic/University
Country United Kingdom
Start 08/2017 
End 09/2017
 
Description Leverhulme Research Grant
Amount £200,000 (GBP)
Organisation The Leverhulme Trust 
Sector Academic/University
Country United Kingdom
Start 10/2015 
End 10/2018
 
Description NSO travel support for S. Candelaresi
Amount £120 (GBP)
Organisation National Solar Observatory (NSO) 
Sector Public
Country United States
Start 05/2016 
End 06/2016
 
Title Coronal Volume Segmentation 
Description Existing image segmentation techniques are applied to coronal volumes and used to identify magnetic domains using quasi-separatrix layers to define domain interfaces. 
Type Of Material Improvements to research infrastructure 
Year Produced 2018 
Provided To Others? Yes  
Impact Method to be made available in 2018. We expect this method to impact the academic community when published. 
 
Description NASA Collaboration 
Organisation National Aeronautics and Space Administration (NASA)
Department Goddard Space Flight Center
Country United States 
Sector Public 
PI Contribution We are designing and running MHD simulations using the ARMS code (Adaptive Refinement MHD Solver) for the investigations of the slow solar wind. This investigation is of mutual interest for the team at NASA, Goddard, who developed the code, and ourselves.
Collaborator Contribution See above.
Impact Will appear under ``Publications".
Start Year 2017
 
Description Northumbria University Solar Physics Research Group 
Organisation Northumbria University
Department Department of Mathematics, Physics and Electrical Engineering
Country United Kingdom 
Sector Academic/University 
PI Contribution We contributed with our expertise in magnetic reconnection, in particular reconnection at magnetic null points, to a joint research project with the Solar Physics Group at Northumbria University on oscillatory magnetic reconnection in the solar atmosphere. The project is supported by the Leverhulme Trust (£200000 in total, Dundee contribution ca £70000) and supports a joint postdoc working on the project for 3 years.
Collaborator Contribution The Northumbria group contributed with their expertise in MHD waves to the project.
Impact Thurgood, J. O., Pontin, D. I. and McLaughlin, J. A. Three-dimensional Oscillatory Magnetic Reconnection, Astrophys. J., 844, 1 (2017). [doi:10.3847/1538-4357/aa79fa]; Thurgood, J. O., Pontin, D. I. and McLaughlin, J. A. Implosive Collapse about Magnetic Null Points: A Quantitative Comparison between 2D and 3D Nulls, Astrophys. J., 855, 50 (2018). [doi:10.3847/1538-4357/aab0a0]
Start Year 2015
 
Description Maths Week Scotland Public Lecture 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach Local
Primary Audience Public/other audiences
Results and Impact Series of short lectures within the Maths Week Scotland, one of which was on Auroras, which is closely related to space weather and the scientific questions addressed in this STFC project.
Year(s) Of Engagement Activity 2017
URL http://www.maths.dundee.ac.uk/news/complexWorlds.pdf
 
Description High School Visit 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach Local
Primary Audience Schools
Results and Impact An afternoon of outreach activities (scientific demonstrations and experiments) for the pupils of a local High School to raise interest in science and mathematics. The teacher gave positive feedback on the uptake of science subjects afterwards.
Year(s) Of Engagement Activity 2016
 
Description Maths Week Scotland 2017 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach Local
Primary Audience Public/other audiences
Results and Impact Researchers from the Universities of Abertay, Dundee, and St Andrews together gave a number of presentations to the general public to highlight how maths can be used to understand the world around us. This included also talks on the solar physics.
Year(s) Of Engagement Activity 2017
URL https://ima.org.uk/7163/maths-week-scotland/
 
Description Maths Week Scotland 2018 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Schools
Results and Impact Researchers from the University of Dundee gave a number of presentations and hands-on workshops to high school students from the local area how maths can be used to understand the world around us. This included also talks on the solar physics.
Year(s) Of Engagement Activity 2018
 
Description School visit (Monifieth) 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach Local
Primary Audience Schools
Results and Impact Presentations were given to groups of school children, which sparked many questions and discussions. Subsequently the school reported increased interest in solar physics, astrophysics, space science
Year(s) Of Engagement Activity 2017
 
Description Schools Visit - Brechin 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach Local
Primary Audience Schools
Results and Impact Presentations were given to groups of school children, which sparked many questions and discussions. Subsequently the school reported increased interest in solar physics, astrophysics, space science
Year(s) Of Engagement Activity 2017
 
Description Schools Visits - Monifieth, Carnoustie 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach Local
Primary Audience Schools
Results and Impact Presentations were given to groups of school children, which sparked many questions and discussions. Subsequently the school reported increased interest in solar physics, astrophysics, space science
Year(s) Of Engagement Activity 2018
 
Description Wednesday Wonders 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach Local
Primary Audience Public/other audiences
Results and Impact Public outreach activity, under the title ``Outer space - Inner space", to which we contributed demonstrations of magnetism and the Sun. This also included a presentation of the virtual reality immersive experience of a flight through the solar atmosphere.
Year(s) Of Engagement Activity 2017
URL http://www.leisureandculturedundee.com/sites/default/files/Activities-Events-Mills_Winter_17-18.pdf