High impact weather in Africa under climate change

Although global climate change is well established, there is an urgent need for new science to understand the consequences of this for changes in high impact weather (e.g. reflected in the “Grand Challenges” of the World Meteorological Organisation). It is this weather that will create the impacts of climate change, whether that is droughts, floods, variable monsoon onsets, or desertification and dust storms. This is particularly true for Africa, where the population is already vulnerable, and this will increase with population growth and climate change. This PhD will address the exciting challenge to better understand possible changes in high impact weather in Africa, combining newly available world-leading simulations with observations, theory and possibly new model runs.

Understanding changes in high impact weather requires a model that can capture the relevant forcings, responses and feedbacks. Global climate models have serious limitations in this regard, since their grid-spacing is too coarse to capture the rain-generating moist convection, and as a result they often fail to capture: the storms that dominate African weather; the links between locally forced circulations and storms; the positive or negative feedbacks that can occur between the land surface and the storms, and therefore changes in extremes. These failures have impacts on the continental scale and feature such as monsoons. Within the Future Climate for Africa programme the Met Office is now running simulations of ten years of past and future climate for the whole of Africa at an unprecedented 4.5 km grid-spacing that for the first time allows explicit modelling of these couplings and feedbacks, providing a complete step-change in model capability. These runs will provide a unique opportunity for this PhD to use to understand changing extremes and high impact weather.

OBJECTIVES

The precise focus of the work depends on the interests of the student and the outcomes of the FCFA programme, although past experience shows that FCAF is likely to only scratch the surface of the understanding that can be gained from the ground-breaking new runs. Likely objectives include:

Initially focusing on East or West Africa, where the supervisors have a wide experience of the relevant meteorology, quantify how the representation of convection controls a selected aspect(s) of high impact weather.

Understand the processes and feedbacks whereby a changed representation of moist convection affects the impact of climate change on the high impact weather.

Key to any research will be bringing new physical understanding to the changes seen in the simulations, using theory, observations and possibly other models, to disentangle mechanisms and feedbacks.

TRAINING SUPERVISION AND THE RESEARCH ENVIRONMENT

You will join a very successful team of scientists, with a broad track record of high-profile research on African weather and climate. You will work with Dr John Marsham who has published 79 papers in 12 years, and has recently been promoted to Associate Professor. He manages a large group working across moist atmospheric convection and associated fields, and his past PhD students have strong records of peer-reviewed publication. Co-supervisor Cathryn Birch is an expert with the Met Office Unified Model and on tropical meteorology.

The Leeds group is involved in 4 of the 5 projects within the Future Climate for Africa (FCFA) Programme, leading major components, and John Marsham leads the consortium addressing East Africa. FCFA ends in July 2019, and the large SWIFT project on African weather forecasting (led from Leeds) is just starting, so you will be joining a strong and dynamic team, with numerous opportunities to learn from postdocs & students working, as well as from supervisors.

SEE provides a large and diverse research environment and you will be encouraged to travel to share your findings and learn from other environments. ICAS has formal partnerships with the Met Office and the Karlsruhe Institute of Technology (KIT, Germany), but travelling further afield is also encouraged. Projects such as FCFA & SWIFT provide opportunities to engage with researchers and practitioners in Africa, and Leeds is often involved in major international field campaigns, which would require further travel.

Environmental and atmospheric modelling is growing field and the PhD will provide hands on experience with a world leading model, and access to appropriate training, for handling the data, for running models and in wider skills.