Spatiotemporal Variation of Continentality in the Mediterranean Region and its Connection to the Atlantic Multidecadal Oscillation

Abstract

This study examines the spatiotemporal evolution of continentality across the Mediterranean region over the period 1950–2023 and explores the relationship between continentality and the Atlantic Multidecadal Oscillation (AMO). Using monthly data from the ERA5-Land reanalysis, three distinct continentality indices (Ivanov, Simple, and Sezer) were calculated to capture regional climate dynamics. The results show a generally insignificant increasing trend in continentality for the entire Mediterranean, driven predominantly by the faster rise in summer maximum temperatures compared to winter minimum temperatures in the western sector. In contrast, slight declines occur in parts of the eastern Mediterranean, where winter warming rates partially offset or balance summer warming. Spatial patterns indicate that continentality increases most prominently in areas such as the interior of the Iberian Peninsula and the Mediterranean islands, where intensified summer temperature anomalies contribute to larger annual temperature ranges. Conversely, the Balkan region, coastal zones of North Africa, and northeastern Türkiye exhibit decreased continentality linked to stronger winter warming. On a multidecadal scale, positive AMO phases generally coincide with higher continentality values, highlighting the influence of large-scale ocean–atmosphere interactions on temperature seasonality in the Mediterranean. Overall, the study underscores the critical role of interseasonal warming trends and atmospheric teleconnections of variability in shaping the region’s continentality, with implications for future climate risk assessments and resource management.