Projected changes in temperature and precipitation indices in Morocco from high-resolution regional climate models
Résumé
The climate of Morocco is characterized by a strong spatial and inter-annual variability. This study provides an evaluation of high-resolution regional climate model (RCM) simulations of precipitation and temperature over Morocco and future projections based on two emission scenarios. The evaluation of the RCM ensemble over the historical period is performed with a network of 20 weather stations, using Taylor and Portrait diagrams. The results show that the four simulations considered (CLM, CNRM, KNMI, IPSL) are generally able to simulate climate indices and no model is performing significantly better. This ensemble of RCM simulations captures the precipitation and temperature spatiotemporal patterns in the evaluation and historical runs. Climate change scenarios are presented with the goal to identify spatial patterns of change over Morocco, to provide information for climate policy and adaptation. The RCP4.5 and RCP8.5 emission scenarios are considered for two time horizons, 2036-2065 and 2066-2095. A large increase in temperature is observed by the end of the century in particular for the RCP8.5 scenario over the Southeast regions. The minimum temperature is expected to increase more than maximum temperature in most parts of Morocco, with the exception of the Eastern regions. The different RCMs show a strong agreement towards similar changes for most temperature-based indices. The climate change signal is less homogeneous in the different simulations for most of the precipitation indices. Nevertheless, there is a clear decrease of precipitation totals in the different simulations, following a North to South gradient. However, for heavy rainfall events, there are strong uncertainties in projections and the four RCM simulations disagree about the future changes.