Saffron Heddell

Profile

I am a final year PhD student in the Institute for Climate and Atmospheric Science (ICAS) within the University of Leed's School of Earth, Environment, and Sustainability (SEES). My work is funded by the NERC Panorama DTP with a CASE partnership from the UK Met Office.

Before studying at Leeds, I did an undergraduate Master's degree in Earth Sciences (Geology) at the University of Durham, where I specialised in mantle geochemistry and volcanology across two dissertation projects focussing on different aspects of Icelandic volcanics. My third-year dissertation project was under the supervision of Dr Richard Brown focussing on the digital mapping of the Askja volcanic system's lava flows and faulting. My fourth-year research project under the supervision of Dr Julie Prytulak using column chemistry to assess whether iron isotopes can be used to track Icelandic mantle sources.

My research interests are driven by my appreciation for the transformative role of large-scale events, such as volcanic eruptions, in shaping the Earth system and influencing life on our planet. This has led to my involvement in projects using laboratory, field, and computational-based methods such as modelling and remote sensing to investigate volcanic systems and their impacts, alongside other hazards. Currently I am continuing my research career by using global modelling to improve our understanding on the impacts of large-scale volcanic eruptions on the stratosphere.

My PhD work focusses on the impact of the water rich, Hunga eruption in 2022 on stratospheric ozone using a combination of the TOMCAT Chemical Transport Model and the Met Office's UKESM alongside satellite observations. My first research chapter assessed the impact of the Hunga eruption's water vapour on the 2023 Antarctic ozone hole, developing on previous publications by separating the vortex into the core and edge regions to consider the influence of the different conditions on the impact. We also briefly compare the impact from the volcanic sulfate aerosol to the water vapour impact with the major result quantifying the chemical impact on the size of the ozone hole. My second research chapter uses both the TOMCAT and UKESM models to investigate the impact of the Hunga eruption on the cold Arctic winter of 2024/25, comparing it to the response in the Antarctic edge region to assess the similarities of the conditions between the two areas. For my third research chapter, I will investigate the dynamical contribution to the stratospheric ozone impact from the Hunga eruption during the 2022 and 2023 Antarctic winters.

Research interests

My main research interests are:

• Large-scale volcanic eruptions – Hunga 2022 (APARC Atmospheric impacts report)
• Stratospheric impacts of volcanic eruptions
• Polar stratospheric ozone chemistry
• Polar stratospheric clouds
• Stratospheric water vapour
• Antarctic ozone hole
• Atmospheric Chemistry Modelling (TOMCAT and UKESM)
• Earth Observation

Previous Research/projects:

• Evaluating the Icelandic mantle source using iron isotopes – 2023, MSci research project, supervised by Dr Julie Prytulak, University of Durham
• Manitou Lake Microbialites – 2022, Mitacs summer internship, supervised by Dr Joyce McBeth, University of Regina (Canada)
• Volcanic evolution of the Askja volcanic system, Iceland – 2022, MSci dissertation project, supervised by Dr Richard Brown, University of Durham

Please get in touch with any queries, collaboration requests, or for further information using eesgh@leeds.ac.uk.

Qualifications

• PhD - University of Leeds (2023 - present)
• MSci (Hons.) Earth Sciences - University of Durham (2019-2023)

Research groups and institutes

• Institute for Climate and Atmospheric Science
• Atmospheric Chemistry and Aerosols