Seasonal and regional changes in temperature projections over the Arabian Peninsula based on the CMIP5 multi-model ensemble dataset

This study explores the seasonal to inter-seasonal and regional changes in temperature (and related uncertainties) over the Arabian Peninsula, by using the multi-model ensemble from the Couple Models Intercomparison Project Phase 5 (CMIP5), under two Representative Concentration Pathway (RCP) scenarios: RCP4.5 and RCP8.5. The seasonal temperature changes are examined for three future periods (2030-2039; 2060-2069 and 2090-2099) with reference to the present climate (1971-2000). The 22-member CMIP5 mean multi-model ensemble (MME) shows a significant increase in temperature (at the 95% confidence level) over the Arabian Peninsula during all three future periods, under both RCPs. The results indicate that the southern and central regions of the Arabian Peninsula are likely to experience larger future temperature changes during the winter and spring seasons. On the other hand, amplification in future temperature changes over the northern and central regions of the Peninsula will more likely occur during the summer and autumn seasons. The interseasonal analysis of the MME shows large temperature biases during the winter (Dec-Feb) and summer (Jun Aug) months, while the simulated results closely resemble the observations during both transition periods i.e. spring (Mar-May) and autumn (Sep-Nov). The inter-seasonal results also reveal larger (smaller) temperature increases during September, October and November (March, April) for all future periods under both RCP4.5 and RCP8.5. Results further indicate that the central region of the Arabian Peninsula will experience higher temperatures during all seasons in the 21st century. This information on changes in projected temperature is valuable for the long-term planning of the region.