Exploring the multi-scaled nature of solar vortices with DKIST (Advert ref: NUDATA23/MPEE/SCULLION)

About the Centre for Doctoral Training

This project is being offered as part of the STFC Centre for Doctoral Training in Data Intensive Science, called NUdata, which is a collaboration between Northumbria and Newcastle Universities, STFC, and a portfolio of over 40 industrial partners, including SMEs, large/multinational companies, Government and not-for profit organisations, and international humanitarian organisations. Please visit https://research.northumbria.ac.uk/nudata/ for information.

PhD project description

Braiding and twisting of magnetic field structures, rooted within the surface of the Sun, has been considered important for understanding the origins of solar atmospheric heating, one of the longest unsolved puzzles in all of astrophysics. Persistent counter-streaming flows at the solar surface layer (known as the photosphere) provides the perfect conditions facilitating magnetic twist, brought about by vortex formation due to turbulent convection. Multi-layer numerical MagnetoHydroDynamics (MHD) of 3D vortex tubes have shown that they are more than adequate to supply enough Poynting flux to heat the solar corona. However, it is not yet known how frequently vortices appear from observations, how correlated they are between the atmospheric layers and how magnetic fields respond to vortices. With the advent of the Daniel K Inouye 4-m Solar Telescope (DKIST) observations, we now have the opportunity to understand the collective nature of solar vortices statistically, at unprecedented spatial and temporal resolution, and to finally confirm the collective contribution of vortices to solar atmospheric heating.

Despite recent advancements in the statistical account of small-scale vortex motions in the solar photosphere, their magnetic fields and heating impacts in the layers above remain unconfirmed. Vortex motion is expected to dictate much of the physics in other twisting phenomena that appear to dominate the chromosphere, including spicules Photospheric vortex flow fields are often inferred from motions of magnetic bright points at intergranular lanes. With the application of a novel fully-automated photospheric vortex identification algorithms, inter-granular photospheric intensity vortices have been detected in large numbers for the first time, with the Swedish 1-m Solar Telescope. At the resolution of 100km, it was proposed that at any time there could be ~1.4x10⁶ photospheric vortices covering about 2.8% of the solar surface. However, in the chromosphere above the photosphere the manifestation of vortices is much more difficult to detect and so far most studies are limited to a handful of events detected “by eye”. In this project, we will develop new approaches to the automated detection of vortices in multiple atmospheric layers with DKIST, in order to understand the 3D nature of vortex tubes channelling energy from the photosphere to the corona. The project aims to exploit new ground-based observations from DKIST in order to accurately quantify:

• a) how many vortices in the photosphere appear as chromospheric vortices (and vice versa)?
• b) how twisted are magnetic fields within vortex tubes in the chromosphere?
• c) how much MHD wave power is excited in chromospheric swirls for basal heating of the corona?

To address the three questions we outline the following three project objectives:

1. Detect, track, characterize and correlate simultaneous vortex flows in both the photosphere and chromosphere, using DKIST observations. Demonstrate the coupling of vorticity between atmospheric layers and understand its importance for energy transfer.
2. Measure changes in the vector magnetic field in the photosphere and chromosphere from DKIST observations in VISP, VBI and VTF. Find evidence of magnetic twist in swirls, for the first time, which is an important feature of numerical models of magnetic tornadoes in delivering Poynting flux.
3. Identify and characterize wave properties, correlations with heating signatures and non-potentiality of magnetic field in a large-scale swirl, co-observed with DKIST and Interface Region Imaging Spectrometer (IRIS).

Recruitment Event

You will join a strong and supportive research team. To help better understand the aims of the CDT and to meet the PhD supervisors, we are hosting a day-long event on campus on Monday 9th January 2023.

At that event, there will be an opportunity to discuss your research ideas, meet potential PhD supervisors, as well as hear from speakers from a variety of backgrounds (academia, industry, government, charity) discussing both STFC and data science as well as their personal paths and backgrounds. Click here for details.

Eligibility Requirements:

• Academic excellence of the proposed student i.e. 2:1 (or equivalent GPA from non-UK universities [preference for 1st class honours]); or a Masters (preference for Merit or above); or APEL evidence of substantial practitioner achievement.
• Appropriate IELTS score, if required.
• Applicants cannot apply for this funding if they are already a PhD holder or if currently engaged in Doctoral study at Northumbria or elsewhere.

Please note: to be classed as a Home student, candidates must meet the following criteria:

• Be a UK National (meeting residency requirements), or
• have settled status, or
• have pre-settled status (meeting residency requirements), or
• have indefinite leave to remain or enter.

If a candidate does not meet the criteria above, they would be classed as an International student.

• Immigration Health Surcharge https://www.gov.uk/healthcare-immigration-application
• If you need to apply for a Student Visa to enter the UK, please refer to the information on https://www.gov.uk/student-visa. It is important that you read this information very carefully as it is your responsibility to ensure that you hold the correct funds required for your visa application otherwise your visa may be refused.
• Check what COVID-19 tests you need to take and the quarantine rules for travel to England https://www.gov.uk/guidance/travel-to-england-from-another-country-during-coronavirus-covid-19

Please note:

You must include the relevant advert reference/studentship code (e.g. NUDATA23/…) in your application.

If you are interested in more than one of the Northumbria-hosted NUdata research projects, then you can say this in the cover letter of your application and you can rank up to three projects you are interested in (i.e. first choice, second choice, third choice). You are strongly encouraged to do this, since some projects are more popular than others. You only need to submit one application even if you are interested in multiple projects (we recommend you submit your application to your first choice).

Deadline for applications: 31st January 2023

Start Date: 25th September 2023