The aim of this study is to describe high resolution sea ice dynamics in relation to wind forcing using the bottom-track facility of the ADCP and icebound drifter buoys. The ADCP detects the presence and movement of the ice pack locally at the installation site while the drifters provide data on the spatial movements of ice packs. The instruments were deployed along a rough cross-section of the Gulf of Finland from Kunda to Kotka. ADCP measurements were performed in the most southern location (59.7 N, 26.4 E) from 12 January-27April 2010. With steps of about 15 nm to the north, two groups of three and two drifting buoys were released on 8 March. The relevant wind data were obtained from the meteorological station on Vaindloo island. In winter 2009-2010 the Gulf of Finland was covered with drift ice and ice-conditions were highly dynamic. Detection of ice cover and ice-free periods based on ADCP bottom-track error velocity values was successful. The rms of bottom-track error velocity for the ice cover periods were about five times smaller than those for the ice-free periods. Altogether five periods of ice cover presence with a duration from 6-12 days were determined at the measurement location. Ice-bound drifters revealed ice dynamics similar to those detected by the ADCP during the measurement period. The alternations of ice conditions, from both ADCP and drifter data, were in accordance with MODIS satellite images. For the ice cover period in March (sub-period C) the correlation coefficient between low-frequency wind and ice drift speeds was as high as 0.91. In accordance with other ice studies, the mean ice-to-wind speed ratio was 3.7% and the mean deviation of ice motion to the right from the direction of the wind vector was 26 degrees.
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