Led by Cath Senior.
Met Office forecast tools are already acknowledged as state-of-the-art, but nevertheless there are still significant limitations in the ability of climate science to support decision making in the developing world. Here we highlight areas of underpinning science that are specifically relevant to improving climate predictions for Africa. We will use the consultation process with African scientists and stakeholders to help prioritise our work to deliver the maximum benefit to decision makers.
Improved forecasting capability for regional climate is required for timescales from months to the next decade. A key focus will be on delivering improved predictions of climate for vulnerable regions of Africa, including predictions of extremes for critical variables such as precipitation. Key modes of tropical variability and local physics will be targeted for improvement through a better understanding and modelling of the driving mechanisms and through higher global model resolution. While predictability in the tropics is higher than for the extra-tropics on seasonal timescales, very detailed simulation of tropical regions is particularly challenging due to complex local processes and a lack of observations. However, we have successfully delivered improvements in simulations of the Asian monsoon and ENSO (El Niño-Southern Oscillation) prediction with our latest model (HadGEM2) through a 'seamless' modelling approach, where knowledge of sources of errors at particular time or space scales can benefit predictions at all timescales. The Met Office has a unified forecast and climate modelling system (MetUM) that runs a single physical modelling system across time and space scales. This means that, for example, we can use new data sources over key regions, such as the intensive observations made as part of the AMMA (African Monsoon Multidisciplinary Analyses) project for evaluation of our models in realtime leading to improvements in models across timescales. In addition, we have evidence from our collaborative work on high resolution modelling, that increased atmosphere and ocean resolution in our global models will give further improvement in some modes of tropical variability (e.g. ENSO) and on the simulation of local physics and extremes - notably tropical cyclones. Again we can benefit from the unified modelling system using modelling studies of local processes (e.g. associated with convection or the land surface) at extremely high resolution (e.g. Cascade*) to improve our regional predictions from global and regional models on seasonal to decadal timescales.
*Cascade is a NERC funded consortium project to study organized convection in the tropical atmosphere using large domain cloud system resolving model simulations. Africa is a key focus region.