Chasing a millennium of European storms: a synthesis of three decades of multidisciplinary research

Abstract. Understanding the long-term variability of coastal storms is essential for assessing future coastal risks in a context of accelerating climate change and sea-level rise. This study synthesizes eighty-one historical and geophysical storm chronologies from western Europe to investigate storm activity over the last millennium. To compare heterogeneous records, a decadal Storm Index (SI) was developed to quantify the relative occurrence of storm impacts within eight geographical regions and was visualized using a novel “storm stripes” approach designed to highlight both temporal and spatial variations in storm activity.

The synthesis reveals substantial regional differences in storm occurrence through time. The decrease in air and Sea Surface Temperatures (SST) since 1300 during the early LIA may have favoured higher storm activity in northern Europe, peaking around 1450–1470 during one of its coolest phases, characterized by weak northern European SST and a significant AMO trough. While the early LIA was mainly driven by NAO+ patterns, transitional NAO+ to NAO- phases may have led to the stormiest periods in the north. Conversely, the increase in air temperature and Mediterranean SST during the late LIA may explain the significant later stormy phase in the western Mediterranean, consistent with a large-scale NAO- phase but with its stormiest peak (1760–1850 AD) linked to a NAO- to NAO+ transitional period at a finer temporal scale. These contrasting patterns appear broadly consistent with variations in the North Atlantic Oscillation, although the influence of other modes of climate variability remains uncertain. By combining historical and geophysical evidence at a continental scale, this study provides a new perspective on the long-term evolution of European coastal storm activity. The results highlight the complexity of storm–climate interactions and demonstrate the value of multidisciplinary paleostorm reconstructions for improving our understanding of future climate adaptation and coastal mitigation strategies.