Multi-decadal drought variability in the Eastern Mediterranean and its connection to large-scale climate indices

Study region Israel, with analysis extending to the Eastern Mediterranean, Europe, and Western Asia. Study focus While traditional agricultural drought indices rely on precipitation and evaporation data, soil-moisture-based indicators may better capture the interactions between climate and local conditions. This study examines the spatiotemporal evolution of drought across Israel, using soil-moisture-based indicators that account for soil physical properties. We analyze long-term changes in agricultural drought indicators using ERA5-Land reanalysis data for two periods (1952–1982, 1992–2022). Next, we examine relationships between drought indicators and large-scale teleconnection patterns. New hydrological insights for the region First, results show a shift from mixed trends in the earlier period to consistent drying in the latter, especially in deeper soil layers and Israel’s semi-arid region, suggesting a northward shift of the aridity line. Next, our results reveal strong correlations between drought indicators and the Atlantic Multidecadal Oscillation (AMO) and the North Sea–Caspian Pattern (NCP), both exceeding 0.5 across most of the study area. These relationships are most pronounced in deeper layers, highlighting the role of slow soil-moisture processes in integrating long-term climatic variability. Additional analysis shows this relationship extends across Europe and Western Asia, indicating a broader spatial influence. The strong, scale-dependent correlations between soil-moisture-based drought indicators and teleconnections suggest potential avenues for enhanced drought monitoring and improved decadal drought predictability in the Eastern Mediterranean and beyond.