Precipitation changes across multiple time scales under SSP scenarios in a semi-arid Mediterranean basin: Uncertainty decomposition and orographic perspective
ATMOSPHERIC RESEARCH, cilt.346, 2027 (SCI-Expanded, Scopus)
- Yayın Türü: Makale / Tam Makale
- Cilt numarası: 346
- Basım Tarihi: 2027
- Doi Numarası: 10.1016/j.atmosres.2026.109408
- Dergi Adı: ATMOSPHERIC RESEARCH
- Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Artic & Antarctic Regions, Compendex, Environment Index, Geobase, INSPEC, Academic Search Ultimate (EBSCO), Engineering Source (EBSCO)
- Karadeniz Teknik Üniversitesi Adresli: Evet
Özet
Climate change is driving profound shifts in hydrometeorological parameters across hotspot regions such as the Mediterranean Basin, placing increasing pressure on water resources management. This study investigates potential future precipitation dynamics in the Susurluk Basin, northwestern T & uuml;rkiye, characterized by a semi-arid and mountainous climate, across multiple time scales for the near future (2030-2059) and the far future (20702099). For this, 14 general circulation models (GCMs) were statistically downscaled to daily time steps for nine stations. The four best-performing models were combined into a multi-model ensemble average, with systematic biases corrected. The projections were assessed under SSP1-2.6, SSP2-4.5, SSP3-7.0, and SSP5-8.5 scenarios, and sources of projection uncertainty were decomposed. The decrease in the orographic gradient, which has not been sufficiently studied in the Mediterranean Basin, has also been examined both observationally and under future scenarios. The results reveal significant annual precipitation declines of -150 to -400 mm at individual stations under the far-future high-emission scenarios. The most pronounced decreases are concentrated in winter (up to 150 mm) and autumn (approximately 125 mm). At the same time, the summer months exhibit limited mean change but a marked amplification of extreme-event variability. Sharp declines were observed, particularly in March, April, November, and December, while in July, despite low absolute values, unusual relative changes of 60-100% were recorded. The spatial analyses show a degradation of the west-to-east orographic precipitation gradient, with precipitation rate per 100 m of elevation declining from 33.3 mm to approximately 28.5-29.1 mm under the high-emission far-future scenarios, signaling a basin-wide transition toward a more homogeneous and arid precipitation regime. Internal variability dominates across most time scales, while GCM structural uncertainty becomes more prominent toward the late century, particularly during summer. These results provide quantitative evidence of the basin's acute sensitivity to anthropogenic climate forcing and underscore the need to revise existing water resources management and flood mitigation strategies to align with high-emission scenarios.