Revealing the Pattern of Solar Alfvénic Waves - RiPSAW

Lead Research Organisation: Northumbria University
Department Name: Fac of Engineering and Environment


This research proposal aims to make advances in our understanding of the physics of our closest star, the Sun, and other solar-like stars. The Sun displays a number of fascinating and dynamic phenomena such as powerful solar flares and giant, planet-sized concentrations of magnetic fields (sunspots). It also provides a unique window that permits us to examine in detail how other stars behave. The Sun is made of a plasma (ionised gas) threaded by a strong magnetic field. Such magnetised plasmas are common throughout the universe (e.g. active galaxy nuclei, nebula, interstellar medium), hence the research will also aid advances across multiple research communities.

Many stars possess their own weather systems, although these systems are extreme compared to those we experience on Earth. In our solar system, a hot, million degree wind blows off the Sun at colossal speeds reaching millions of miles per hour, washing over the planets. While we are under the protection of the Earth's magnetic field, that deflects the Sun's wind, other planetary bodies in the solar system have been exposed to its influence. For example, the Sun's wind is known to have stripped Mars of its atmosphere. Scientists are also interested in how these winds will influence the habitability of exoplanets around other Sun-like stars. These winds also contribute to how the stars evolve, with the Sun losing over 10 trillion tonnes of material each year via its winds.

The objectives of the RiPSAW project are to examine a new mechanism related to the generation of the hot plasma and powerful winds, focusing on the role of magnetic waves. These magnetic (or Alfvén) waves are able to transfer energy through a star's atmosphere and are considered an important feature of any magnetic star. Exciting results from Dr Morton's recent observations of the Sun have found evidence that the magnetic waves are excited high in the atmosphere by sound waves leaking out from the inside of the Sun. This challenges our current knowledge of how energy is transported through a stars' atmosphere, hence the proposed work may transform the understanding of how these hot winds behave.
To address these fundamental, yet unanswered, questions, RiPSAW makes use of advanced mathematical techniques and cutting-edge computer simulations to create models of the Sun based on magnetohydrodynamics. We combine this theoretical effort with the highest quality data of the Sun available from state-of-the-art solar instruments (e.g. NASA's Solar Dynamic Observatory); incorporating information from across the electromagnetic spectrum (e.g. visible, EUV) and analysing this with modern methods drawn from statistics and machine learning.

Planned Impact

To enable the RiPSAW project to deliver impact, I have identified a number of different groups who might benefit from the proposed project. These are:

* Children, young people, their families and teachers across primary schools in the North East. In particular, focusing on schools with potential low science-capital and are typically underserved by current outreach/engagement initiatives.
* Young adults with a burgeoning interest in STEM careers.
* UK and EU academics in the Solar Physics community wishing to engage, and improve their public engagement and outreach.

The goals for the proposed impact, and potential benefits, revolve around an ongoing theme that cross-cuts a number of research councils, namely that the UK (and other nations) face a shortage of people with STEM skills and qualifications. This is also entwined with the current gender imbalance seen across many areas of STEM, and highlighted by the lower proportion of females graduating in core STEM subjects. Hence, the proposed pathways aim to play a role in helping to address these issues, contributing to impact in the broad areas of understanding, learning and participation, and social welfare.

In particular, I aim to:
* Increase aspirations of children & young people such that they can identify themselves with scientists and science/STEM-related careers.
* Engage with teachers and families of the young children to demonstrate and identify the range of routes into and careers in STEM.
* Foster interests in young adults, sixth form and undergraduate, who have shown interest in pursuing STEM into higher education or as career.
* Develop key technical and professional skills of young adults associated with STEM subjects through knowledge transfer.
* Provide resources, training and skill transfer to interested academics who wish to either begin delivering meaningful public engagement, or improve their current practice.

The impact will be achieved through a mixture of existing pathways related to ongoing initiatives, funded by the STFC and EU Horizon 2020, as well as pathways to be developed and implemented solely for RiPSAW.


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Description The science supported by this award is to examine the journey of magnetic waves (known as Alfvénic waves) through the Sun's atmosphere. One area of interest is how these waves can heat the Sun's atmopshere, and what processes turn the energy carried by the waves into heat. One of the findings so far is that a process called phase mixing, often discussed in the scientific literature, appears not be efficient in the most of the Sun's atmosphere. We came this conclusion by examining how much the waves are damped in observational data of the Sun's corona. Hence, any heating by Alfvénic waves will have to happen by another mechanism.
Exploitation Route Our finding on phase mixing of Alfvenic waves (Tiwari et al. 20201 Morton et al. 2021) helps to define the journey of these waves through the Sun's atmosphere. And it should direct other researchers, who undertake theoretical and numerical modelling of waves in the Sun's atmopshere, to focus their attention on other processes.

Our measurements of the correlation length of Alfvenic waves helps to understand the conditions of energy input into the Sun's corona. The correlation length is key parameter in models of Alfvénically-driven solar and stellar winds, used to predict solar wind conditions and study the habitability of exoplanets. Hence, our results provide a constraint for researchers who undertake theoretical and numerical modelling of Alfvénically-driven winds, enabling the reduction of uncertaintity in the models.
Sectors Other

Description Software development for the uCoMP instrument 
Organisation High Altitude Observatory (HAO)
Country United States 
Sector Academic/University 
PI Contribution We are working with HAO to develop software for the analysis of data from the new Upgraded Coronal MultiChannel Polarimeter (uCoMP). We have written the data analysis software in Python. It has been tested and verified against an existing codebase and also synthetic data. The software has been made open-access via GitHub. A tutorial for the user communtiy was given at the UCoMP workshop (Boulder, USA) in 2023.
Collaborator Contribution Partner has provided expertise on uCoMP instrument.
Impact Development of python-based software that is freely available.
Start Year 2020