Winter Barents–Kara Sea ice loss preconditions a summer drought corridor across Eastern Europe and Eurasia

Droughts are becoming increasingly severe and widespread across Eurasia, with major consequences for agriculture, public health, and regional economies. Although declining Arctic sea ice has been linked to midlatitude climate extremes, the directionality and physical robustness of its relationship with summer drought remains uncertain. Here, we apply a multi-method framework, based on observational data, that integrates statistical analyses with information flow diagnostics, predictive autoregressive models, and physical diagnostics. Using more than a century of sea ice concentration (SIC) and drought observations, together with high-resolution atmospheric reanalysis data, we show that reduced winter Barents–Kara Seas SIC is robustly linked to dry conditions along a continental corridor extending from eastern Romania, Moldova, and Ukraine across the northern Black Sea and Caspian regions into Kazakhstan. Over half of the statistically significant drought-affected area is simultaneously supported by both the information flow and predictive autoregressive analyses. Physical diagnostics indicate that reduced winter sea ice is followed by circulation anomalies consistent with an Arctic dipolar pressure response, enhanced jet stream waviness, and a planetary-scale circulation pattern spanning the North Atlantic and Eurasia. The resulting anticyclonic circulation north of the Caspian Sea is consistent with atmospheric stagnation, warm and dry air advection, and reduced cloud cover along the identified drought corridor. These findings identify winter Barents-Kara Seas SIC as a potential source of information for probabilistic summer drought prediction and could provide an observational benchmark for future climate model experiments. As Arctic sea ice continues to decline, the identified corridor may become increasingly relevant for agriculturally vulnerable regions already exposed to geopolitical instability, extending from Eastern Europe to Central Asia.