Design sea ice conditions for offshore wind power in the Baltic Sea

Sea ice conditions in the northern Baltic Sea (north from the latitude 56.8 0 N) were determined based on the past ice charts from the period of 1980/81 to 2021/22 created by the Finnish Ice Service. The scope of the study was in the parameters relevant for structural design of offshore wind turbines such as the maximum level ice thickness occurring once in 50 years, ice season length, the existence of ice ridges, ice type and ice thickness histograms. It was noted that the ice conditions vary significantly in different areas and site-specific estimation of ice conditions is important. The harshest ice conditions were met in the northern part of the Bay of Bothnia where ice was met every year, and the average ice season length was up to 180 days. • A unique database for the northern Baltic Sea (North from 56.8 0 N) was created. • It is based on navigational ice charts from winter 1980/81 to winter 2021/22. • Sea ice parameters relevant for structural design of offshore wind power are studied. • It can be utilized in sea ice assessments for offshore wind turbine structures.