Characteristics of high-resolution sea ice dynamics in the Gulf of Finland, Baltic Sea

High-resolution Eulerian and Lagrangian sea ice kinematics are examined based on an ADCP and four icebound drifting buoys in the Gulf of Finland, Baltic Sea. The measurements were performed in the central Gulf of Finland in winter 2010 from January to March. Ice drift was mostly in near-free drift state driven by winds and ice-independent currents in the basin. Internal friction was significant, apart from off-ice forcing toward the open boundary. The averaged asymptotic ice/wind speed ratio and deviation angle at higher wind speeds were 0.034 and 9 degrees in the oceanic boundary layer, respectively. The ratio depended on the direction of the wind indicating the role of morphometry of the coast to the local ice kinematics. The maximum values of wind ratio were observed in cases of NE winds and minimum values in cases of SW winds. Coherent ice drift was observed up to a distance of 42 km.