Precipitation distribution over Africa: observations and modeling

This chapter investigates spatial and temporal characteristics of precipitation across Africa, a continent highly reliant on precipitation for various socioeconomic activities. Using observational data and Coupled Model Intercomparison Project Phase 6 (CMIP6) models, our results show distinct precipitation patterns over different subregions. West Africa receives its highest precipitation during the summer monsoon period of June-September, and central Africa's precipitation is year-round, with a rainy (dry) period occurring from May to September in north (south) Eastern Africa, while southern Africa's highest precipitation occurs during the Southern Hemisphere summer. The CMIP6 models, alongside their ensemble mean, generally capture the seasonal peaks of precipitation, although with noticeable biases. For instance, the models underestimate (overestimate) precipitation intensity over northern (sub-Saharan) Africa. Also, the models struggle to reproduce the spatial characteristics of the observed precipitation variability, timing of rainy season onset and cessation, and some extreme precipitation indices. Overall, this chapter underscores the importance of refining climate models, which is critical for developing credible projections of future changes to inform policy and management decisions across Africa's diverse landscapes and economies.