An ensemble of regional climate simulations is analysed to evaluate the ability of ten regional climate models (RCMs) and their ensemble average to simulate precipitation over Africa. All RCMs use a similar domain and spatial resolution of ~50km and are driven by the ERA-Interim reanalysis (1989-2008). They constitute the first set of simulations in the CORDEX-Africa project. Simulated precipitation is evaluated at a range of time scales, including seasonal means, annual and diurnal cycles, against a number of detailed observational datasets. All RCMs simulate the seasonal mean and annual cycle quite accurately, although individual models can exhibit significant biases in some sub-regions and seasons. The multi-model average generally outperforms any individual simulation, showing biases of similar magnitude to differences across a number of observational data sets. Moreover, many of the RCMs significantly improve the precipitation climate compared to that from their boundary condition data set - ERA-Interim. A common problem in the majority of the RCMs is that precipitation is triggered too early during the diurnal cycle, although a small subset of models do have a reasonable representation of the phase of the diurnal cycle. The systematic bias in the diurnal cycle is not improved when the ensemble mean is considered. Based on this performance analysis, it is assessed that the present set of RCMs can be used to provide useful information on climate projections over Africa.
Tweets by SantanderMeteo
