The Climate Cluster has a major focus on African climate led by Richard Washington. We research historical African climate from the instrumental and satellite record as well as the ability of models to simulate this complex climate system.
There are two key strands of research. First, we are interested in the climate processes that control current and future rainfall amounts. This work includes improving estimates of projected future rainfall and efforts to reduce the uncertainty associated with those projections. Second, we work on aerosols, specifically mineral aerosols or dust. Africa is the largest source of mineral aerosols on the planet.
Project IMPALA: Improving Model Processes for African Climate
This project, jointly funded by the Department for International Development and the Natural Environment Research Council (NERC), aims to deliver a step change in predictive capability for Africa on 5 to 40 year timescales. IMPALA is led by the Met Office working alongside Richard Washington and Rachel James (both in the School of Geography) and Philip Stier in Atmospheric, Oceanic and Planetary Physics at the University of Oxford. Oxford leads the Model Evaluation component of the project, with links to ongoing work by Richard Washington’s group to explore regional climate dynamics in climate models and observed datasets, including two DPhil projects by Callum Munday and Amy Creese, focusing on southern and central Africa respectively. Oxford has also contributed to the development of the model aerosol scheme following on from progress made in the NERC-funded DO4Models and Fennec projects.
IMPALA features very high resolution (4 km) continent-wide model simulations. At these spatial scales models simulate convection without the limits of parameterisation which have long been problematic in the representation of rainfall from convective clouds. Oxford works in conjunction with five African-based partners at the University of Cape Town, University of Yanounde I, University of Nairobi, the African Centre of Meteorological Application for Development in Niamey, Niger and KNUST in Ghana. IMPALA forms part of the Future Climate for Africa programme.
Project UMFULA: Uncertainty reduction in Models for Understanding Development Applications
UMFULA is a project which focuses on climate variability and change on 5 to 40 year timescales in southern and central Africa. It aims to address the causes of climate projection uncertainty through extensive process-based model evaluation. UMFULA is a component of the Future Climate for Africa research programme, jointly funded by the UK Department for International Development and the Natural Environment Research Council. Its focus is not only to advance scientific knowledge and predictive ability, but also to better integrate science into longer-term decision making and risk management.
Thus far the climate science at Oxford has a particular focus on:
- the structure of water vapour transport over central Africa in both reanalysis and coupled climate models;
- the definition of the Angola Low, its causes and representation in coupled models;
- tropical-temperate cloud band dynamics, their links to El Nino and La Nina and their representation in coupled climate models and high resolution (c.4km grid spacing) nested models.
Project CLARIFY: CLoud-Aerosol-Radiation Interactions and Forcing
The representation of clouds, aerosols and cloud-aerosol-radiation impacts remain a large uncertainty in climate change, limiting our ability to accurately reconstruct and predict future climate change. The south-east Atlantic is a region where high atmospheric aerosol loadings from biomass burning and semi-permanent stratocumulus cloud are co-located, providing a natural laboratory for studying the full range of aerosol-radiation and aerosol-cloud interactions and their perturbations of the Earth’s radiation budget.
CLARIFY is a major consortium programme consisting of five UK universities (Exeter, Oxford, Leeds, Manchester and Reading) with project partners from the UK Met Office, European universities and research institutes, the US NSF ONFIRE (ObservatioNs of Fires Impact on the southeast Atlantic Region) and US NASA ORACLES (ObseRvations of Aerosols above CLouds and their interactions).
Ground-based observations for CLARIFY have been organised from Oxford. An array of aerosol sampling equipment was set up on Etosha Pan in Northern Namibia. Instruments included a Cimel photometer, Dusttrak aerosol sampler, radiometers, automatic weather stations measuring temperature, wind, pressure, etc. and a Halo-Photonics Lidar system. In addition, aerosol measurements were made on the Skeleton coast near the Huab river (Cimel, Dusttrak, automatic weather station, passive aerosol samplers). Richard Washington leads the ground-based instrument deployment in CLARIFY.
For a summary of African climate research, please visit africanclimateoxford.net.