How well do the CORDEX-CORE simulations capture the seasonal variation of rainfall in East Africa?

Agriculture in East Africa is rain-fed and, thus, depends on the occurrence of precipitation. Given its location around the equator, the occurrence of precipitation in East Africa is characterized by marked seasonality with either one rainy season centred around local summer in the regions that are further away from the equator (except for the Horn of Africa) and two rainy seasons in the regions near the equator and at the Horn of Africa in boreal autumn and boreal spring.
In this study, the extent to which the simulations contributing to the CORDEX-CORE experiment Africa represent the seasonal variation of rainfall in East Africa realistically is investigated. These are simulations for recent decades with three different regional climate models, either forced with observed lateral meteorological boundary conditions or with data from global climate simulations with three different models. The CHIRPS data are considered as observational data of daily rainfall. The seasonal variation of rainfall is described by the characteristics of the mean annual cycle of daily rainfall, e.g., whether it is dominated by an annual or a semi-annual variation, as well as by the timing, i.e., the onset and cessations dates, and the length of the prominent rainy seasons.
The realistic representation of the seasonal variation of rainfall in East Africa in the regional climate simulations is crucial for the validity of future climate scenarios simulated by the respective models and, thus, the potential future impacts of climate change on agriculture in East Africa.