Projected precipitation and temperature changes in the Middle East—West Asia using RegCM4.7 under SSP scenarios

The projection of precipitation changes and the year of surpassing a 1, 2, 3, 4, and 5 °C warming above pre-industrial levels in the Middle East – West Asia (MEWA) during 2026–2100 was conducted using dynamical downscaling of the Regional Climate Modeling version 4.7 (RegCM4.7) under Shared Socio-economic Pathways (SSPs) scenarios. Two significant changes in annual precipitation were identified compared to the baseline period of 1990–2014: a decrease in the Mediterranean Basin (MB) and an increase in the Persian Gulf- the Gulf of Oman -east of the Arabian Peninsula region (POA). The above patterns were also detected during the spring of 2026–2050. However, a decrease in precipitation is anticipated around the Persian Gulf (PG) during 2076–2100. The precipitation patterns exhibit a decrease in the MB and east of it up to Iran during the summer. In contrast, there is an increase in precipitation in the POA. During autumn, precipitation increases (decreases) around the POA (MB). During the winter, there is an increase (decrease) in the precipitation of POA (from the MB to Iran). In the SSP5-8.5 scenario, a 2 °C (3 °C) warming is expected by 2050 (2068), about two (four) decades earlier than SSP2-4.5. A 4 °C (5 °C) warming is expected by 2081 (2092) in SSP5-8.5, but postponed beyond 2100 in SSP2-4.5. Out of all studied cities, Tehran is projected to experience the greatest decrease in precipitation and the highest increase in temperature. Meanwhile, Abu Dhabi is expected to encounter the greatest precipitation increase and the lowest temperature rise.