A 2,500-year coastal Scottish speleothem record of North Atlantic winter storm-track variability

Coastal western Scotland lies directly under the core of the modern North Atlantic winter storm track, yet long winter-sensitive terrestrial archives of storminess are rare. We present a new 2,500-year (~600 BCE–1981 CE), high-resolution speleothem record from a sea cave on the Isle of Islay, a uniquely winter-dominated site that captures past changes in storm activity, moisture pathways, and North Atlantic hydroclimate. This multiproxy record, comprising stable isotopes (δ¹⁸O, δ¹³C) and marine aerosol-related elements (Na, S), reflects the combined influence of Atlantic westerlies, sea-spray transport, and seasonal recharge.Islay δ¹⁸O and δ¹³C reflect changes in the pathway and hydrological processing of Atlantic winter moisture. Lower values occur during intervals with enhanced effective recharge and stronger Atlantic influence, such as the Roman and Medieval Warm Periods. In contrast, higher values reflect reduced recharge and colder circulation regimes during the Dark Age Cold Period and Little Ice Age. Sodium concentrations rise during these cold intervals, indicating enhanced sea-spray delivery and intensified winter storminess, while sulphur reflects mixed sea-salt and non-sea-salt marine aerosol inputs.Comparison with Greenland ice core data shows that Islay Na covaries with Greenland Na⁺, and that major volcanic events (e.g., 1257 CE) produce synchronous S maximum in both regions. These teleconnected responses demonstrate that coastal Scotland and Greenland share common winter storm generation processes and Arctic–Atlantic moisture variability. This study provides the first long-term speleothem–ice-core teleconnection framework for reconstructing North Atlantic winter storm-track behaviour over the past 2,500 years.