Dr Leighton Regayre

Dr Leighton Regayre


I have experience working as an applied statistician in agriculture and climate sciences, and for over a decade I taught secondary school mathematics and led maths departments. I have participated in and led several large research projects as a postdoctoral researcher and PI including:

  • The FORCeS project (FORCeS), 2021 – present
  • CSSP-China, 2018 - 2021
  • The Aerosol-Cloud Uncertainty REduction project (A-CURE), 2017 - 2021
  • Securing Multidisciplinary UndeRstanding and Prediction of Hiatus and Surge events (SMURPHS), 2015 - 2017
  • Copernicus Atmospheric Monitoring Service: Climate Forcings (CAMS 74), 2015 - 2017

I'm an active member of our institute. I'm currently the postdoctoral representative and have previously assumed the roles of postgraduate student representative and internal seminar organiser.


  • ICAS PDRA representative

Research interests

I'm currently conducting research as part of the FORCeS project which will constrain aerosol effective radiative forcing and deliver improved climate projections. We will sample model uncertainty in multiple processes that affect aerosols, clouds, radiaiton and their interactions, then reduce that uncertainty using process-based observational constraints. Within the NERC-funded ACURE project, led by Prof Ken Carslaw, we tackled the aerosol forcing uncertainty through a comprehensive synthesis of aerosol, cloud and atmospheric radiation measurements, combined with innovative ways to analyse global model uncertainty. We produced a large set of model variants (a perturbed parameter ensemble, or PPE) that spans the uncertainty in multiple model parameters. Advanced statistical methods were used to generate essentially millions of model simulations that enable the full uncertainty of the model to be explored. The spread of these simulations were then be narrowed by comparing the simulated aerosols, clouds and aerosol-cloud relationships against extensive measurements. Yet, substantial uncertainty remains. Within FORCeS we will strategically constrain the remaining uncertainty using a suite of observations informed by our understanding of the climate system.

My PhD (2012-2016) research identified the causes of uncertainty in the aerosol-cloud interaction component of the aerosol effective radiative forcing over multiple forcing periods and multiple regions of climatic importance. In my thesis I presented an analsis of the causes of model uncertainty in aerosol radiative forcing and for the first time aerosol effective radiative forcing (including rapid atmospheric adjustments). This analysis revealed the important regional, seasonal and anthropogenic emission period differences in the main causes of uncertainty. I analysed the causes of uncertainty in climatically important regions where aerosols are understood to affect dynamical systems on the decadal scale. My research has highlighted the importance of both aerosol and physical atmosphere parameters as causes of uncertainty in aerosol effective radiative forcing. I've also shown that satellite measurements of top-of-the-atmosphere radiative fluxes do provide some constraint on aerosol forcing uncertainty. But, I've also shown that the constraint is limited because accounting for multiple causes of uncertainty means there are many observationally-plausible ways of getting the same result. I'm interested in finding combinations of measurements that provide a strong constraint on aerosol forcing uncertainty. Reducing this important source of model uncertainty will greatly improve model skill at making climate projections.

<h4>Research projects</h4> <p>Any research projects I'm currently working on will be listed below. Our list of all <a href="https://environment.leeds.ac.uk/dir/research-projects">research projects</a> allows you to view and search the full list of projects in the faculty.</p>


  • PhD, Research Excellence, Aerosol radiative forcing uncertainty, University of Leeds
  • MSc, Atmosphere and Ocean Dynamics, University of Leeds
  • BSc (Hons), University of Queensland
  • QTS, Qualified Teacher Status, Bradford College
  • ULTA-1, University of Leeds Teaching Award - Level 1 (Merit), University of Leeds

Professional memberships

  • Associate Fellow of the Higher Education Academy
  • American Geophysical Union
  • Priestley International Centre for Climate

Student education

I have over a decade of teaching and leadership experience in secondary Mathematics education. At the University of Leeds I have tutored multiple Applied Mathematics and Statistics courses within the School of Earth and Environment and the School of Mathematics. In 2015 I was awarded the University of Leeds Teaching Award (ULTA-1) and developed my ability to deliver highly-accessible learning opportunities for students. In 2020-2021 I lectured on the level 2 modules ‘Data Analysis and Visualisation’ and ‘Climate Change: Science and Impacts’.

Research groups and institutes

  • Institute for Climate and Atmospheric Science
  • Atmospheric Chemistry and Aerosols
<h4>Postgraduate research opportunities</h4> <p>We welcome enquiries from motivated and qualified applicants from all around the world who are interested in PhD study. Our <a href="https://phd.leeds.ac.uk">research opportunities</a> allow you to search for projects and scholarships.</p>