20.500.12556/DiRROS-24196 Climate change reflected in 40-year isotopic composition trends of precipitation in Slovenia Long-term monitoring of stable isotopes in precipitation (δ18O, δ2 H), alongside meteorological data, is key to understanding how large-scale hydroclimate variability influences regional and local climate. This study presents one of the longest records in Central and Southeastern Europe: the multi-decadal (1981–2024) dataset of monthly composite precipitation stable isotope records from Ljubljana, Slovenia. The δ18O, δ2 H, and d-excess values are increasing (+0.02 ‰, +0.18 ‰, and +0.05 ‰ per year, respectively), consistent with regional warming. Seasonal patterns were evident, with elevated d-excess values during autumn. The decomposition of the δ18O, δ2 H and d-excess time series using Hilbert-Huang Transform revealed statistically significant annual oscillations in all variables. These oscillations correlated strongly with the annual oscillation of temperature, but a lag of 2–3 months was identified for d-excess. Lower-frequency (multi-year) oscillations of d-excess were also observed. HYSPLIT back-trajectory analysis confirmed a significant contribution of Mediterranean-sourced air masses to autumn precipitation, but did not explain d-excess oscillations. Similar results were observed also for coastal (Portoroˇz, Slovenia) and continental (Vienna, Austria) stations. The findings imply an accelerating, exponential-like isotopic response to warming that has already propagated into the water cycle, providing isotope evidence that precipitation-surface water-groundwater interactions in investigated region changed in last decade. precipitation stable isotopes trend analysis Hilbert-Huang transform ensemble empirical mode decomposition HYSPLIT true false true Elsevier Nizozemska Angleški jezik Ni določen © 2025 The Authors. Neznano 2025-11-19 14:33:44 2025-11-19 14:33:44 2025-11-20 03:44:44 0000-00-00 00:00:00 2026 0 0 Nasl. z nasl. zaslona; Soavtorji: Klara Žagar, István Gábor Hatvani, Zoltán Kern, Polona Vreča; Opis vira z dne 13. 11. 2025; str. 1-11 Vol. 288, [article no.] 123286 2026 0000-00-00 Zaloznikova Objavljeno NiDoloceno 2025-09-30 2025-11-05 2025-11-05 551.58 1096-0953 257145603 https://www.sciencedirect.com/journal/environmental-research 1 62df72de-c54c-11f0-94a7-001a4af901a5 https://dirros.openscience.si/Dokument.php?lang=slv&id=36035 RAZ_Gacnik_Jan_2026.pdf RAZ_Gacnik_Jan_2026.pdf 1 284464877DF7B84BAB9CD8FA4C097644 61d27c8343f710b715ca6770a56f4d2f500f875e561b54bcc9e36600ed630b72 b4334713-c54c-11f0-94a7-001a4af901a5 https://dirros.openscience.si/Dokument.php?lang=slv&id=36036 Institut Jožef Stefan 0 0 0