Temporal variability of precipitation isotopes in Damascus, Syria — implications for regional climate change

Abstract Records of stable isotopes ( 2 H and 18 O), deuterium excess d -excess) tritium 3 H) values in precipitation (P) during 1990–2022, together with long-term time series (1919–2022) air temperature (T) P-amount at the Damascus station, were analysed to explore seasonal annual variability patterns those parameters P assess vulnerability climate change this area. Variation average T over period 1919–1969 shows an increase gradient ≈ + 0.1 °C/decade. However, a remarkable much higher (+ 0.64 °C/decade) is calculated for 1990–2022. The value last three decades (≈185 mm) was lower by ≈28 mm, compared (≈213 mm), relative reference (1919–1969). This significant decline ≈11–13%, accompanied heating 0.2–0.6 °C/decade T, likely result affecting linear relationships between δ O versus 1990–2019 indicate increased gradients both (≈0.3–0.5‰ ≈1.1–3.2‰ per decade H, respectively), decrease ≈0.9–1.1‰ -excess values. Variability concentrations towards low levels (< 6 TU) later years strongly suggests return back cosmogenic production radioisotope upper atmosphere. Information gained from work would offer new insights improve understanding temporal risks associated on natural water resources Eastern Mediterranean region.