Abstract
The objective of this analysis is to provide an up-to-date observation-based assessment of the evolution of temperature extremes in the Middle East–North Africa (MENA) region and evaluate the performance of global climate model simulations of the past four decades. A list of indices of temperature extremes, based on absolute level, threshold, percentile and duration is used, as defined by the Expert Team on Climate Change Detection and Indices (ETCCDI). We use daily near-surface air temperature (Tmax and Tmin) to derive the indices of extremes for the period 1980–2018 from: (i) re-analyses (ERA-Interim, MERRA-2) and gridded observational data (Berkeley Earth) and (ii) 18 CMIP5 model results combining historical (1950–2005) and scenario runs (2006–2018 under RCP 2.6, RCP 4.5 and RCP 8.5). The CMIP5 results show domain-wide strong, statistically significant warming, while the observation based ones are more spatially variable. The CMIP5 models capture the climatology of the hottest areas in the western parts of northern Africa and the Gulf region with the thewarmest day (TXx) > 46 °C and warmest night (TNx) > 33 °C. For these indices, the observed trends are about 0.3–0.4 °C/decade while they are 0.1–0.2 °C/decade stronger in the CMIP5 results. Overall, the modeled climate warming up to 2018, as reflected in the indices of temperature extremes is confirmed by re-analysis and observational data.
Highlights
The global average air temperature near the Earth’s surface has increased by approximately 1 ◦ C above the pre-industrial levels and this warming was likely due to man-made forcing by increased green-house gas (GHG) levels, as reported in the Intergovernmental Panel on Climate Change (IPCC)Special Report on Global Warming of 1.5 ◦ C [1]
The 1980–2018 climatology of selected indices for the Middle East–North Africa (MENA) region are presented in Figures 1–4, with maps of TXx, TNx, Warm Spell Duration (WSDI), TX90p, respectively
First we examine the climatology of the absolute maxima of daily maximum and minimum temperature (TXx and TNx, or warmest day and warmest night, respectively) in Figures 1 and 2
Summary
The global average air temperature near the Earth’s surface has increased by approximately 1 ◦ C above the pre-industrial levels and this warming was likely due to man-made forcing by increased green-house gas (GHG) levels, as reported in the Intergovernmental Panel on Climate Change (IPCC)Special Report on Global Warming of 1.5 ◦ C [1]. In situ observations reveal widespread significant changes in temperature extremes consistent with warming, especially for those indices derived from daily minimum temperature over the whole 110 years of record but with stronger trends in more recent decades [3]. In this global background, the Middle East–North Africa (MENA) region emerges as a climate change hotspot, with temperature increases and rainfall reductions since the middle of the 20th century [4,5,6,7]. Several studies based on long-term temperature station data suggest that since the 1970s, Atmosphere 2020, 11, 813; doi:10.3390/atmos11080813 www.mdpi.com/journal/atmosphere
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
