About the Project
Background
There is an urgent need for reliable assessments of high-impact weather under climate change. This is true globally, but Sub-Saharan Africa is not only highly vulnerable, but presents unique challenges for climate prediction. Moreover, African climate planning typically focus on 5-30 year timescales, where we need to account for interactions between climate change and multi-year variability. Tropical weather is dominated by convection, which is poorly captured in global models. Now,…
convection-permitting models (CPMs) can provide improved predictions of extremes, often revealing greater increases. CPMs are, however, computationally costly and represent a limited sample of potential climate change uncertainties, with almost no assessment of how this interacts with climate variability. Machine-learning provides an opportunity to capture the added value of CPMs, to expose how high impact weather may change, accounting for both natural variability and climate change.
PhD Project
How do we explore how interactions of climate variability and change are likely to impact Africa? We have rich information on variability and change from global model experiments, but lack the impact on Africa. The Met Office has a new world-leading ensemble of high-resolution CPMs for Africa that explicitly model the rain-generating convective storms that especially important for extremes. However, their vast computational cost has limited these simulations to sample only a few multi-year datasets that are insufficient to address uncertainties from interactions of variability and climate change.
This project will develop machine-learning (ML) approaches to downscale global models. The CPMs over Africa provide data to train ML to relate large-scale circulation (that is modelled in current climate projections) to local scale weather (that usually requires the CPMs to model).
Objectives
- Incorporate current physical understanding on the drivers of tropical weather into the development, benchmarking, and evaluation of key phenomena for tropical weather features key to climate risk, including mesoscale convective systems (MCSs).
- Use these benchmarks to train and improve ML downscaling for tropical and sub-tropical Africa.
- Use ML capability to explore, for the first time, how interactions between climate variability and climate change may impact African at a local, impact relevant, scales, and the associated uncertainties. The resulting local datasets will represent tools which capture the dominant drivers of uncertainty on timescales of years, and with which to explore this climate hazard from a variety of approaches, (such as risk or narrative based framings, including for rare events).
The student will be working alongside a Gates and FCDO funded project developing similar approaches, but for application to sub-seasonal predictions. This will provide opportunities for collaboration in the UK and Africa.
Applicant Profile
The project will provide exciting opportunities for students with a strong background in maths, physics, statistics, computer science or meteorology, who want to develop machine-learning tools to provide improved projections. There may be opportunities to travel to Africa, but this is not essential. Visits to the UK Met Office will facilitate collaboration with the Met Office co-supervisor, as well potentially with other scientists there.
Funding Notes
This project is part of the UNRISK CDT, which offers 15-18 fully-funded NERC studentships, covering full university tuition fees; a personal stipend at standard UKRI rates; £6000 individual research and training costs; £5000 (per student) of cohort-level training; and a ‘Flexible Fund’ for special projects.
International applicants will need to cover costs related to applying for a student visa and the international health surcharge (IHS)
Applications are open to UK and international applicants. The number of awards for international applicants is limited by UKRI rules.
More information is available on the UNRISK website: View Website
References
Senior et al., 2021 (Convection-Permitting Regional Climate Change Simulations for Understanding Future Climate and Informing Decision-Making in Africa, https://journals.ametsoc.org/downloadpdf/journals/bams/102/6/BAMS-D-20-0020.1.pdf) describes the predecessor to the new convection-permitting simulations for Africa that will be used in this PhD.
The Kendon et al, 2025 outlook (Potential for Machine Learning Emulators to Augment Regional Climate Simulations in Provision of Local Climate Change Information, https://journals.ametsoc.org/view/journals/bams/106/6/BAMS-D-24-0114.1.xml) tries to outline the potential for AI tools to translate global climate information down to local, impact relevant, scales. This includes outlining some of the open challenges.
Project supervisors
Prof. John Marsham
Career overview
Prof. John Marsham is a Professor of Atmospheric Science at the School of Earth and Environment at the University of Leeds. He received a PhD in Meteorology from the University of Edinburgh in 2003, following an MPhys in Physics with 1st class honours from the same institution in 1999. Prof. Marsham leads a research group focused on atmospheric convection, tropical meteorology, climate change, and Saharan dust uplift. His research aims to bridge process studies with practical implications for weather and climate models. He has been recognised for his contributions to the field, receiving the Royal Meteorological Society's L F Richardson prize in 2009 and the European Meteorological Society's Young Scientist Award in 2010 for his outstanding publications. Prof. Marsham is also involved in teaching, leading the Climate Risk module of the MSc in Climate Futures and supervising undergraduate and postgraduate dissertations.
Research interests
Prof. Marsham's research focuses on atmospheric convection, precipitation, climate change, and tropical meteorology, particularly in Africa. He is interested in weather prediction across time-scales, mesoscale and boundary-layer dynamics, and dust uplift and transport. His work aims to enhance understanding of these processes and their implications for weather and climate models. Prof. Marsham leads a research group that conducts process studies related to these topics, contributing to improvements in predictive models.