Maritime operations in ice-covered waters: A 25-year data-driven study of baltic sea ice conditions and icebreaker-ship operations

• Delivers the first long-term, data-driven insights into Baltic Sea ice navigation. • Presents a full-spectrum characterization of Baltic Sea ice conditions. • Analyzes quantitative insights into icebreaker-ship operation features. • Provides regional mapping revealing distinct operational metrics and patterns. • Establishes a comprehensive foundation for improving maritime resilience in ice-covered waters. Climate change and evolving shipping patterns have increased attention on navigation in ice-covered waters, where harsh environmental conditions may lead to operational disruptions and emergency situations. The Baltic Sea represents a distinctive case in which intensive maritime traffic coincides with pronounced seasonal sea ice variability. During winter, navigation depends on a coordinated system of icebreaker assistance and regulatory measures to maintain continuity of transport under ice-induced constraints. This study presents a 25-year data-driven analysis of ice conditions and icebreaker-ship operations in the Baltic Sea, providing a systematic empirical characterization of long-term winter navigation practices. Drawing on comprehensive datasets of ice extent, thickness, and duration, the paper generates a new spectrum combing ice thickness and ice day. With detailed operational records of icebreaker-assisted activities, the study quantifies spatial and temporal patterns in assistance demand, fleet deployment, and navigational performance across subregions. The results offer an integrated perspective on maritime operations in ice, contributing to a consolidated empirical foundation for understanding winter navigation and evidence-based discussion on resilience and emergency preparedness in ice-affected maritime transport environments.