PhD

My PhD focusses on using helioseismic techniques to analyse the subsurface properties of the Sun. I assess the frequency shifts in of pressure modes ( also known as p-modes; standing sound waves in the Sun generated by convective flows) observed by the GONG network and MDI/HMI over the past two solar cycles to examine the Quasi-Biennial Oscillation (QBO). The QBO has a period of roughly two-years and it's origins continue to be hotly debated. Understanding the generation mechanism of the solar QBO will pave the way to a fuller understanding of the Sun's magnetic dynamo, which has significant implications for Space weather and its associated hazards.

My work also examines the presence and properties of quasi-periodic pulsations (QPPs) seen in solar and stellar flares. Although many generation mechanisms have been proposed for QPPs, none have yet been confirmed. My research examines the stationarity of QPPs using observational data from GOES using a periodogram based approach.

I am supervised by Dr. Anne-Marie Broomhall, and am STFC funded.

Teaching and additional modules

Successfully completed Deep (Machine) Learning for PhysicistsLink opens in a new window module, using Keras, FastAI, TensorFlow and Pytorch (2021)

Successfully completed Science CommunicationLink opens in a new window module as part of the Postgraduate Certificate in Transferable Skills in Science (PGCTSS) (2019)

Senior Graduate Class Teacher for undergraduate students, leading weekly sessions to up to 25 students covering Electricity and Magnetism, Physics Foundations, Classical mechanics, Special Relativity, Thermal Physics, and Quantum phenomena (2018 - 2021)

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Outreach and Public Engagement

I also take a keen interest in public engagement and improving access for minorities in STEM. In 2022 I was awarded the Postgraduate Warwick Award for Public and Community Engagement (WAPCE) partly due to my work with STEM Connections, in which I created a activity aimed at the intersection of art and science. The activity 'Embroider a Sunquake!' has been showcased to over 500 students and has been exhibited at the National Astronomy Meeting 2022 and the Caithness International Science Festival 2022.

I have also spoken at a number of 'Pint of Science' public lectures: "What to do when the Sun throws a temper tantrum" (2018) , "Who would win in a fight; the Sun or a billion lions?" (co-written and co-presented with Dr. Alun Rees, 2019), and "Escaping the Sun: a photon's 100,000 year journey" (Watchable on Youtube, 2021)

I've also regularly spoken at Warwick's Christmas Lectures to audiences of 1000+. In 2018 this was alongside Dr. Anne-Marie Broomhall on "Do you hear that Star Singing? Unveiling the music of helioseismology". In 2020, the Christmas Lectures moved online, and I presented "How to measure distances in space: The astronomical ruler" (Watchable on Youtube, 2020). Since 2021, I have been invited back annually as a guest co-presenter at the Christmas Lectures.

If you are planning an outreach event, or want to discuss improving inclusion etc. please get in touch! STEM Ambassador (DBS checked), with certification in Child Protection Fundamentals.

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Previous education

Masters degree: "Investigating the behaviour of quasi-periodic pulsations (QPPs) in solar flares using Empirical Mode Decomposition", MRes, University of Warwick, supervised by Prof. Valery Nakariakov, 2017-18

Bachelors degree: Applied Mathematics and Theoretical Physics, BSc. (Hons), University of St. Andrews, 2014-17

My Github page can be found here: github.com/TaraAthem

My LinkedIn page can be found here: www.linkedin.com/in/tishtrya-mehtaLink opens in a new window

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Publications

Prevalence of non-stationarity in Quasi-Periodic Pulsations (QPPs) associated with M- and X- class solar flares

Mehta, T., Broomhall, A.-M., Hayes, L. (2022), (Submitted to Monthly Notices of the Royal Astronomical Society)

Reach out, touch space

Mehta, T., McDonald, C., Nealon, B. (2022), Astronomy & Geophysics

Cycle dependence of a quasi-biennial variability in the solar interior

Mehta, T., Jain, K., Tripathy, S.C., Keifer, R., Kolotkov, D., Broomhall, A.-M. (2022), Monthly Notices of the Royal Astronomical Society

A blueprint of state-of-the-art techniques for detecting quasi-periodic pulsations in solar and stellar flares

Broomhall, A-M., Davenport, J., Hayes, L., Inglis, A., Kolotkov, D., McLaughlin, J., Mehta, T., Nakariakov, V., Notsu, Y., Pascoe, D., Pugh, C. and Van Doorsselaere, T. (2019), Astrophysical Journal Supplement Series

Non-stationary quasi-periodic pulsations in solar and stellar flares
Nakariakov, V. M., Kolotkov, D. Y., Kupriyanova, E. G., Mehta, T., Pugh, C. E., Lee, D. H., Broomhall, A.-M. (2018) Plasma Physics and Controlled Fusion

Email: t.mehta.1@warwick.ac.uk

Office: PS1.07
Pronouns: She/ hers.

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