Comparison of multi-model ensembles of global and regional climate model projections for daily characteristics of precipitation over four major river basins in southern Africa. Part II: Future changes under 1.5 °C, 2.0 °C and 3.0 °C warming levels

This study examines the change in daily characteristics of seasonal precipitation under 1.5 °C, 2.0 °C, and 3.0 °C global warming levels (GWLs) above the pre-industrial period over four southern African basins. We compare the projected changes among large ensembles of climate models during sub-seasons of the rainy season. In particular, we used future projections under the highest emission scenario from the Coupled Model Intercomparison Project (CMIP) versions 5 and 6, the Coordinated Regional Climate Downscaling Experiment (CORDEX), and the Coordinated Output for Regional Evaluations (CORE). The results show that all ensemble projects increase in the length of dry spells (CDD) and daily rainfall intensity (SDII), while wet spell duration (CWD) and the number of rainy days (RR1) will decrease under all GWLs. However, discrepancies are found in the signs of change for indices of heavy precipitation (R10mm and R20mm), especially among regional climate model (RCM) ensembles (CORDEX and CORE). The discrepancies among RCM ensembles may be associated with the difference in spatial resolution, number of downscaled global climate models (GCMs) and downscaling RCMs. Spatial inconsistencies are also found in terms of the magnitude and robustness of future changes under all GWLs. Overall, the projected changes are uncertain over most parts of the basins in CMIP6, whereas CORE projects a stronger signal and larger areas of robust changes over the basins under all GWLs compared to other ensembles.

SAMUEL Sydney;  DOSIO Alessandro;  MPHALE Kgakgamatso;  NSADISA FAKA Dieudonne;  WISTON Modise; 

2023-07-28

ELSEVIER SCIENCE INC

JRC132051

0169-8095 (online),   

https://www.sciencedirect.com/science/article/pii/S0169809523003186,    https://publications.jrc.ec.europa.eu/repository/handle/JRC132051,   

10.1016/j.atmosres.2023.106921 (online),