Robust future climate projections for Europe

Overview

This PhD project offers the exciting opportunity to perform cutting edge climate research alongside leading scientists at the University of Leeds, the Met Office, the National Center for Atmospheric Research (NCAR) in the USA and Imperial College London. The focus of the PhD is on the important topic of regional climate projections, which has been identified as a Grand Challenge for climate science by the World Climate Research Programme. The focus will be on advancing the science for projections of North Atlantic and European climate, which have been hampered for a long time by low confidence and poor agreement amongst climate models. You will undertake visits to the Met Office, NCAR and Imperial College and learn to perform and analyse climate model simulations using state-of-the-art computer modelling and data analysis tools.

        

The research problem

To mitigate the worst impacts of climate change, decision-makers require knowledge of the risk of high impact weather and climate events. In the UK and Europe, the jet stream and storm track sit at the heart of many weather and climate extremes. Future projections from different climate models show opposite trends in the jet stream (Shepherd, 2014), leading to large uncertainties in the estimated risk of floods, wind storms and heat waves. Current climate projections are therefore of limited value for decision-makers. This PhD will tackle this challenge head on by developing robust future climate projections for Europe and the North Atlantic region.

Recent studies have identified serious limitations of climate models in simulating North Atlantic weather and climate. This includes underestimating predictable variations in the jet stream (Scaife and Smith, 2018; Smith et al., 2020) and underestimating multi-decadal variability (Simpson et al., 2018). The causes of this behaviour are currently unknown and rectifying these problems is a matter of urgency for the climate prediction community.

Tantalising results suggest that North Atlantic climate simulations improve at very high resolutions (at scales smaller than 10 km) (Scaife et al., 2019). This may be because air-sea coupling is important in the North Atlantic, for example through interaction of sharp sea surface temperature fronts and weather systems (Czaja et al., 2019), but these processes are generally poorly simulated in standard models. New advances in computing capabilities mean we are now at the dawn of being able to simulate these processes in much more detail. This PhD project will investigate the hypothesis that mesoscale air-sea interactions play an important role for European climate projections and that correctly capturing these processes produces more robust future projections. These hypotheses will be tested through a cutting-edge ultra-high-resolution modelling framework using the world-leading Met Office Hadley Centre and Community Earth System Models.

Potential applicants should contact the lead supervisor (a.c.maycock@leeds.ac.uk) before applying.

Figure 1: Simulation of Met Office Hadley Centre global climate model at a resolution of around 10 km. Courtesy P.L. Vidale, M. Roberts, G. Perez.

Objectives

The specific objectives of the project will be adapted to fit the interests of the student and to pursue the most promising avenues of enquiry. Specific research objectives could include:

  • Use observations and state-of-the-art model simulations to investigate the importance of air-sea coupling for North Atlantic weather systems
  • Perform and analyse ultra-high-resolution global climate model simulations and determine whether the North Atlantic jet stream is more realistically represented when small scale processes are resolved
  • Investigate the impact of model errors in remote regions outside of the Atlantic (such as in the Pacific) on European climate projections using a novel ‘nudging’ technique that allows the model to mimic observations

The topics each offer the potential for innovative cutting-edge research and also freedom for the student to expand the research in the direction of their own interests.

Research tools

You will have access and training in using state-of-the-art modelling and high performance computing systems, including the new ARCHER2 supercomputer and the new Met Office supercomputer that will be installed in 2022, which is expected to be the world’s most advanced dedicated to weather and climate. Through expert training, you will develop excellent technical skills in computer programming, performing model simulations and data visualisation. You will use new observation-based datasets and two world-leading climate models from the Met Office and NCAR to perform novel experiments to improve European climate projections.

International Network

The project is co-supervised by scientists from the Met Office, NCAR and Imperial College. You will visit the Met Office Hadley Centre to discover the latest research and operations in the Monthly to Decadal Prediction and High Resolution Modelling groups led by co-supervisors Prof Adam Scaife and Dr Malcolm Roberts, respectively. You will undertake an extended visit to NCAR to work with Dr Isla Simpson, an expert in atmospheric dynamics, on analysing cutting edge high resolution experiments being performed with the Community Earth System Model 2. You will have the opportunity for regular visits to Imperial College London to work with Dr Arnaud Cjaza, an expert in mesoscale processes and air-sea coupling.

The student will benefit from being part of the EU CONSTRAIN project, a vibrant international research program involving 13 research institutes aimed at reducing uncertainty in climate projections, which is led by the University of Leeds.

Key outputs and potential for high impact

The project addresses a major and fundamental question in climate science that is closely aligned with high priority activities of strategic importance to the Met Office. There have been a series of recent high-profile papers published (e.g., Scaife and Smith, 2018; Smith et al., 2020) from the Met Office highlighting problems with current climate predictions for the North Atlantic and Europe. This project will seek solutions to these problems.

There is international recognition of the growing need for reliable climate projections to inform the public, policy makers and stakeholders. This project will address this need by advancing capabilities for North Atlantic climate projections. The results of the project, in the form of more robust climate projections for Europe, will be valuable to the UK Climate Projections (UKCP) team and the 2022 UK Climate Change Risk Assessment Exercise.

Training and research support

You will join a vibrant and dynamic group of academic staff, PhD and postdoctoral researchers within the Physical Climate Change and Dynamics and Clouds research groups in the Institute for Climate and Atmospheric Science (ICAS) at the University of Leeds. We meet regularly providing a supportive forum to discuss latest research and ideas. More widely, ICAS provides a welcoming community to build a broad background in research topics across atmospheric and climate science including through seminars and lectures.

You will benefit from an excellent wider research environment that includes technical support through the Centre for Environmental Modelling and Computing, access to Met Office models and data through the Leeds-Met Office Academic Partnership, and the Priestley International Centre for Climate, which promotes interdisciplinary climate research in Leeds. The Centre offers both a student society and the opportunity to apply to a PhD Scholars program. You will be part of the NERC Doctoral Training Partnership (DTP) PANORAMA cohort, which fosters a lively community amongst departments and provides many dedicated research, training and social opportunities.

The supervision team are all world-leading experts in their fields and will provide the student access to a large network of international scientists and activities. This includes projects within the World Climate Research Programme, the Intergovernmental Panel on Climate Change Assessment Reports, the Coupled Model Intercomparison Projects, and the National Center for Atmospheric Research in Boulder Colorado, a world-leading centre for climate science and modelling. You will have numerous opportunities to present your research at national and international conferences and meetings (e.g., European Geosciences Union, American Geophysical Union assemblies), as well as to attend summer schools and other training workshops.

Specific skills that will be developed during the project include:

  • Techniques to handle the large data sets produced by models.
  • Application of statistical analysis methods to model simulations.
  • Understanding of sources of uncertainty in projections.
  • Use of observational datasets to evaluate model simulations.
  • Effective communication through presentations at conferences, informal talks at project meetings, and writing peer-reviewed journal articles.
  • Working with people from a range of backgrounds.

Entry requirements

A good first degree (1 or high 2:1), Masters degree or equivalent in a physical or mathematical discipline such as Physics, Mathematics, Meteorology, Climate Science, Environmental/Geophysical Sciences, Engineering or Computer Sciences. A desire to learn new programming and modelling techniques is essential.

Further reading

If you are unable to access any of these studies please email the lead supervisor.

Czaja, A., Frankignoul, C., Minobe, S. et al. Simulating the Midlatitude Atmospheric Circulation: What Might We Gain From High-Resolution Modeling of Air-Sea Interactions?. Curr Clim Change Rep 5, 390–406 (2019). https://doi.org/10.1007/s40641-019-00148-5

Scaife, A.A., Smith, D. A signal-to-noise paradox in climate science. npj Clim Atmos Sci 1, 28 (2018). https://doi.org/10.1038/s41612-018-0038-4

Scaife, AA, Camp, J, Comer, R, et al. Does increased atmospheric resolution improve seasonal climate predictions? Atmos Sci Lett. 2019; 20:e922. https://doi.org/10.1002/asl.922

Shepherd, T. Atmospheric circulation as a source of uncertainty in climate change projections. Nature Geosci 7, 703–708 (2014). https://doi.org/10.1038/ngeo2253

Simpson, I. R., C. Deser, K. A. McKinnon, and E. A. Barnes, 2018: Modeled and Observed Multidecadal Variability in the North Atlantic Jet Stream and Its Connection to Sea Surface Temperatures. J. Climate, 31, 8313–8338, https://doi.org/10.1175/JCLI-D-18-0168.1.

Smith, D.M., Eade, R., Scaife, A.A. et al. Robust skill of decadal climate predictions. npj Clim Atmos Sci 2, 13 (2019). https://doi.org/10.1038/s41612-019-0071-y

Smith, D.M., Scaife, A.A., Eade, R. et al. North Atlantic climate far more predictable than models imply. Nature 583, 796–800 (2020). https://doi.org/10.1038/s41586-020-2525-0