A positive phase of the winter North Atlantic oscillation is associated with drought in Central Europe the following summer

Abstract

More frequent and severe droughts in Central Europe threaten water security and ecosystem resilience. The winter North Atlantic Oscillation (NAO), which regulates much of Europe’s hydroclimate, increasingly drives summer drought propagation across the region. Here we combined a process-based, isotope-enabled ecohydrological model with teleconnection diagnostics, large-scale reanalysis, field observations and drought indices to link continental-scale winter circulation variability to local drought propagation through the Soil–Plant–Atmosphere Continuum (SPAC) in a representative lowland catchment of the North European Plain. Positive winter NAO phases show a significant teleconnection with reduced summer precipitation, associated with subsequent summer drought evident from coupled deficits in soil moisture, streamflow and groundwater, with lag periods of up to ten months. The mechanistic analysis suggests that this cross-seasonal linkage is associated with spring–summer precipitation deficits linked to persistent Arctic sea-ice anomalies from late winter into summer, as well as enhanced early-season vegetation productivity. The NAO–hydroclimate relationships show temporal evolution, with strengthening lagged summer linkages, potentially amplified by climate change. This NAO – SPAC integration advances understanding of drought propagation potentially improving prediction and resilience planning in Europe’s drought-sensitive lowlands.